very strange. maybe it would be more flexible?
#ifdef LIBMYSQL_VERSION_ID // use MYSQL >= 5.6
WPFatal(mysql_get_client_version() == LIBMYSQL_VERSION_ID, "Used MySQL library version (%s) does not match the version used to compile TrinityCore (%s).",
mysql_get_client_info(), MYSQL_SERVER_VERSION);
#else
WPFatal(mysql_get_client_version() == MYSQL_VERSION_ID, "Used MySQL library version (%s) does not match the version used to compile TrinityCore (%s).",
mysql_get_client_info(), MYSQL_SERVER_VERSION);
#endif