Fix for bug #1160 : reset time_zone

lib/MySQL_Session.cpp

@@ -961,7 +961,7 @@ bool MySQL_Session::handler_again___verify_backend_sql_mode() {
 bool MySQL_Session::handler_again___verify_backend_time_zone() {
 	if (mybe->server_myds->myconn->options.time_zone_int==0) {
 		// it is the first time we use this backend. Set time_zone to default
-		if (mybe->server_myds->myconn->options.time_zone==NULL) {
+		if (mybe->server_myds->myconn->options.time_zone) {
 			free(mybe->server_myds->myconn->options.time_zone);
 			mybe->server_myds->myconn->options.time_zone=NULL;
 		}

lib/mysql_connection.cpp

@@ -1665,6 +1665,11 @@ void MySQL_Connection::reset() {
 			free(options.sql_mode);
 			options.sql_mode = NULL;
 		}
+		options.time_zone_int = 0;
+		if (options.time_zone) {
+			free(options.time_zone);
+			options.time_zone = NULL;
+		}
 	}
 	delete local_stmts;
 #ifndef PROXYSQL_STMT_V14