Fix m4 quoting on configure error messages.

The error message quoting for the Sphinx check failure was removed in
c2d4999, but is actually needed.

If you omit the quoting, the error turns into this:

    checking for python3 script directory (pythondir)... ${PYTHON_PREFIX}/lib/python3.11/site-packages
    checking for python3 extension module directory (pyexecdir)... ${PYTHON_EXEC_PREFIX}/lib/python3.11/site-packages
    checking for ... /usr/local/bin/python3 -m sphinx
    checking for sphinx version >= 1.7.5... No module named 'sphinx'
    ./configure: line 441: test: check: integer expression expected
    configure: error: Sphinx
    ./configure: line 312: return: check: numeric argument required
    ./configure: line 322: exit: check: numeric argument required

Signed-off-by: James Peach <jpeach@apache.org>

Author: jpeach

configure.ac

@@ -345,13 +345,13 @@ AC_ARG_ENABLE([docs],
       TS_MAN8_MANPAGES=`cd $srcdir/doc && $PYTHON manpages.py --section=8 | $AWK '{print "$(BUILDDIR)/man/" $0 }' | tr '\n' ' '`
     ], [
       enable_doc_build=no
-      AC_MSG_ERROR(Doc building disabled, Python 3.4 or better required)
+      AC_MSG_ERROR([Doc building disabled, Python 3.4 or better required])
     ])
 
     AS_IF([test -z "$JAVA"],
       [
         enable_doc_build=no
-        AC_MSG_ERROR(Doc building disabled, Java required but not found)
+        AC_MSG_ERROR([Doc building disabled, Java required but not found])
       ])
     AC_ARG_VAR(SPHINXBUILD, [the sphinx-build documentation generator])
     AC_ARG_VAR(SPHINXOPTS, [additional sphinx-build options])
@@ -362,7 +362,7 @@ AC_ARG_ENABLE([docs],
       ],[
         sphinx_version_check=no
         enable_doc_build=no
-        AC_MSG_ERROR(Doc building disabled, check Sphinx installation)
+        AC_MSG_ERROR([Doc building disabled, check Sphinx installation])
       ])
 
 
@@ -704,7 +704,7 @@ AC_COMPILE_IFELSE([
     AC_MSG_RESULT(yes)
     ], [
     AC_MSG_RESULT(no)
-    AC_MSG_ERROR([*** A compiler with support for -std=c++$CXXSTD is required.])
+    AC_MSG_ERROR([A compiler with support for -std=c++$CXXSTD is required])
 ])
 AC_LANG_POP
 CXX="$ac_save_CXX"
@@ -1011,13 +1011,13 @@ fi
 # Flags for ASAN
 if test "x${enable_asan}" = "xyes"; then
   if test "x${enable_tsan}" = "xyes" -o "x${enable_tsan}" = "xstatic"; then
-    AC_MSG_ERROR(Cannot have ASAN and TSAN options at the same time, pick one)
+    AC_MSG_ERROR([Cannot have ASAN and TSAN options at the same time, pick one])
   fi
   TS_ADDTO(AM_CFLAGS, [-fno-omit-frame-pointer -fsanitize=address])
   TS_ADDTO(AM_CXXFLAGS, [-fno-omit-frame-pointer -fsanitize=address])
 elif test "x${enable_asan}" = "xstatic"; then
   if test "x${enable_tsan}" = "xyes" -o "x${enable_tsan}" = "xstatic"; then
-    AC_MSG_ERROR(Cannot have ASAN and TSAN options at the same time, pick one)
+    AC_MSG_ERROR([Cannot have ASAN and TSAN options at the same time, pick one])
   fi
   asan_CXXFLAGS="$CXXFLAGS"
   CXXFLAGS="$CXXFLAGS -fno-omit-frame-pointer -fsanitize=address -static-libasan"
@@ -1028,7 +1028,7 @@ elif test "x${enable_asan}" = "xstatic"; then
     [AC_MSG_RESULT([yes])],
     [
       AC_MSG_RESULT([no])
-      AC_MSG_ERROR(Cannot find static ASAN library.)
+      AC_MSG_ERROR([Cannot find static ASAN library])
     ]
   )
   AC_LANG_POP
@@ -1040,23 +1040,23 @@ fi
 # Flags for LSAN stand-alone mode
 if test "x${enable_lsan}" = "xyes"; then
   if test "x${enable_asan}" = "xyes" -o "x${enable_asan}" = "xstatic"; then
-    AC_MSG_ERROR(ASAN already specified, --enable-lsan is meant only for LSAN stand-alone mode)
+    AC_MSG_ERROR([ASAN already specified, --enable-lsan is meant only for LSAN stand-alone mode])
   fi
   if test "x${enable_tsan}" = "xyes" -o "x${enable_tsan}" = "xstatic"; then
-    AC_MSG_ERROR(Cannot have LSAN and TSAN options at the same time, pick one)
+    AC_MSG_ERROR([Cannot have LSAN and TSAN options at the same time, pick one])
   fi
   TS_ADDTO(AM_CFLAGS, [-fno-omit-frame-pointer -fsanitize=leak])
   TS_ADDTO(AM_CXXFLAGS, [-fno-omit-frame-pointer -fsanitize=leak])
 elif test "x${enable_lsan}" = "xstatic"; then
   if test "x${enable_asan}" = "xyes" -o "x${enable_asan}" = "xstatic"; then
-    AC_MSG_ERROR(ASAN already specified, --enable-lsan is meant only for LSAN stand-alone mode)
+    AC_MSG_ERROR([ASAN already specified, --enable-lsan is meant only for LSAN stand-alone mode])
   fi
   if test "x${enable_tsan}" = "xyes" -o "x${enable_tsan}" = "xstatic"; then
-    AC_MSG_ERROR(Cannot have LSAN and TSAN options at the same time, pick one)
+    AC_MSG_ERROR([Cannot have LSAN and TSAN options at the same time, pick one])
   fi
   AC_CHECK_LIB(lsan, _init, [lsan_have_libs=yes], [lsan_have_libs=no])
   if test "x${lsan_have_libs}" == "xno"; then
-    AC_MSG_ERROR(Cannot find LSAN static library)
+    AC_MSG_ERROR([Cannot find LSAN static library])
   fi
   lsan_CXXFLAGS="$CXXFLAGS"
   CXXFLAGS="$CXXFLAGS -fno-omit-frame-pointer -fsanitize=leak -static-liblsan"
@@ -1067,7 +1067,7 @@ elif test "x${enable_lsan}" = "xstatic"; then
     [AC_MSG_RESULT([yes])],
     [
       AC_MSG_RESULT([no])
-      AC_MSG_ERROR(Cannot find static LSAN library.)
+      AC_MSG_ERROR([Cannot find static LSAN library])
     ]
   )
   AC_LANG_POP
@@ -1083,7 +1083,7 @@ if test "x${enable_tsan}" = "xyes"; then
 elif test "x${enable_tsan}" = "xstatic"; then
   AC_CHECK_LIB(tsan, _init, [tsan_have_libs=yes], [tsan_have_libs=no])
   if test "x${tsan_have_libs}" == "xno"; then
-    AC_MSG_ERROR(Cannot find TSAN static library)
+    AC_MSG_ERROR([Cannot find TSAN static library])
   fi
   tsan_CXXFLAGS="$CXXFLAGS"
   CXXFLAGS="$CXXFLAGS -fsanitize=thread -static-libtsan"
@@ -1094,7 +1094,7 @@ elif test "x${enable_tsan}" = "xstatic"; then
     [AC_MSG_RESULT([yes])],
     [
       AC_MSG_RESULT([no])
-      AC_MSG_ERROR(Cannot find static TSAN library.)
+      AC_MSG_ERROR([Cannot find static TSAN library])
     ]
   )
   AC_LANG_POP
@@ -1107,15 +1107,15 @@ fi
 # TODO: Later this is irrelevant, and we should just bail on 32-bit platforms always
 AC_CHECK_SIZEOF([void*])
 if test "x$ac_cv_sizeof_voidp" == "x"; then
-  AC_MSG_ERROR(Cannot determine size of void*)
+  AC_MSG_ERROR([Cannot determine size of void*])
 fi
 
 # Right now, 32-bit platform is a build error, unless we've forced it with --enable-32bit-build
 if test "${ac_cv_sizeof_voidp}" = "4"; then
    AS_IF([test x"$enable_32bit_build" = "xyes"], [
      AC_MSG_NOTICE([Explicitly building on a 32-bit platform, this might be unsupported soon!])
    ], [
-     AC_MSG_ERROR(You are trying to build on a 32-bit platform, which is unsupported.)
+     AC_MSG_ERROR([You are trying to build on a 32-bit platform, which is unsupported])
    ])
 fi
 
@@ -1379,7 +1379,7 @@ AM_CONDITIONAL([BUILD_JA3_PLUGIN], [test "x${enable_ja3_plugin}" = "xyes"])
 # Check for zlib presence and usability
 TS_CHECK_ZLIB
 if test "x${enable_zlib}" != "xyes"; then
-  AC_MSG_ERROR([Cannot find zlib library. Configure --with-zlib=DIR])
+  AC_MSG_ERROR([Cannot find zlib library, configure --with-zlib=DIR])
 fi
 
 #
@@ -1417,7 +1417,7 @@ AC_CHECK_FUNCS(malloc_usable_size)
 #
 TS_CHECK_PCRE
 if test "x${enable_pcre}" != "xyes"; then
-  AC_MSG_ERROR([Cannot find pcre library. Configure --with-pcre=DIR])
+  AC_MSG_ERROR([Cannot find pcre library, configure --with-pcre=DIR])
 fi
 
 # Check for optional brotli library
@@ -1433,7 +1433,7 @@ if test "${has_quiche}" = "1"; then
 if test "$openssl_is_boringssl" = "1" ; then
 enable_quic=yes
 else
-  AC_MSG_ERROR([Use of BoringSSL is required if Quiche is used.])
+  AC_MSG_ERROR([Use of BoringSSL is required if Quiche is used])
 fi
 fi
 TS_ARG_ENABLE_VAR([use], [quic])