Remove saving/updating GTID repo when maxscale starts

Remove saving/updating GTID repo when maxscale starts.
The repo update slows down the maxscale startup.
The saving was added in order populate GTID repo with current file but
it costs extra time to event validation routine when current binlog has
many events and it has a big size.

server/modules/routing/binlogrouter/blr_file.c

@@ -2848,8 +2848,6 @@ blr_read_events_all_events(ROUTER_INSTANCE *router,
                 /* Update Last Seen MariaDB GTID */
                 strcpy(router->last_mariadb_gtid,
                        router->pending_transaction.gtid);
-                /* Save MariaDB 10 GTID */
-                blr_save_mariadb_gtid(router);
             }
 
             total_events += transaction_events;