MDEV-17093: SOURCE_REVISION in log (postfix - not in help)

Don't display the source revision in the mysqld --help output.

sql/mysqld.cc

@@ -5249,6 +5249,7 @@ static int init_server_components()
     Print source revision hash, as one of the first lines, if not the
     first in error log, for troubleshooting and debugging purposes
   */
+  if (!opt_help)
     sql_print_information("Starting MariaDB %s source revision %s as process %lu",
                           server_version, SOURCE_REVISION, (ulong) getpid());