Set mysqlmon timeouts to 10 seconds

The backend timeouts should help prevent disconnections.

maxscale-system-test/cnf/maxscale.cnf.template.mysqlmon_rejoin_manual

@@ -13,9 +13,9 @@ failcount=1
 allow_cluster_recovery=true
 replication_user=repl
 replication_password=repl
-backend_connect_timeout=3
-backend_read_timeout=3
-backend_write_timeout=3
+backend_connect_timeout=10
+backend_read_timeout=10
+backend_write_timeout=10
 auto_failover=true
 
 [RW Split Router]