Fix dbclient -m help and -c help w/out hostname. #305

Job	Run time
build (plain linux)	46s
build (multi binary, 1, 1)	46s
build (multi binary, dropbearmulti argv0, 1, 1)	46s
build (client only, no, PROGRAMS=dbclient)	23s
build (server only, no, PROGRAMS=dropbear)	25s
build (bundled libtom, bionic , no writev(), ubuntu-20.04, --enable-bundled-libtom --enable-werro...	44s
build (linux clang, clang)	51s
build (c89, -std=c89 -Wdeclaration-after-statement, 1, --enable-pam)	43s
build (macos 14, macos-14, clang, -Wno-deprecated-declarations -Wno-undef, no, no, ranlib -no_war...	1m 2s
build (macos 12, macos-12, clang, -Wno-deprecated-declarations -Wno-undef, no, no, ranlib -no_war...	59s
build (DEBUG_TRACE, 1, --enable-pam, #define DEBUG_TRACE 5 )	57s
build (nondefault options, 1, --enable-pam)	45s
build (most options disabled, --disable-harden --disable-zlib --disable-openpty --disable-lastlog...	24s
build (other algo combos, no, #define DROPBEAR_SHA1_HMAC 0 #define DROPBEAR_RSA_SHA1 0 #define DR...	25s
	9m 56s

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