Increase the timeouts different_size

A slight increase of the timeout to 300 seconds should solve some test
failures. The test is extremely hard on the machines and even when run
locally, the test slows down to a crawl.

maxscale-system-test/different_size.cpp

@@ -81,7 +81,7 @@ void different_packet_size(TestConnections* Test, bool binlog)
         {
             size_t size = 0x0ffffff * i + j;
             Test->tprintf("Trying event app. %lu bytes", size);
-            Test->set_timeout(240);
+            Test->set_timeout(300);
 
             char* event = create_event_size(size);
             conn = connect_to_serv(Test, binlog);