src: guard bundled_ca/openssl_ca with HAVE_OPENSSL

Currently, the following warning will be reported when configuring
without-ssl:

../src/node.cc:3653:8: warning: unused variable 'use_bundled_ca'
[-Wunused-variable]
  bool use_bundled_ca = false;
       ^
../src/node.cc:3654:8: warning: unused variable 'use_openssl_ca'
[-Wunused-variable]
  bool use_openssl_ca = false;
       ^

I missed this when working on
commit 8a7db9d ("src: add
--use-bundled-ca --use-openssl-ca check").

Refs: nodejs#12087
PR-URL: nodejs#12302
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

src/node.cc

@@ -3783,6 +3783,10 @@ static void ParseArgs(int* argc,
   const char** new_v8_argv = new const char*[nargs];
   const char** new_argv = new const char*[nargs];
   const char** local_preload_modules = new const char*[nargs];
+#if HAVE_OPENSSL
+  bool use_bundled_ca = false;
+  bool use_openssl_ca = false;
+#endif  // HAVE_INSPECTOR
 
   for (unsigned int i = 0; i < nargs; ++i) {
     new_exec_argv[i] = nullptr;