As the wait_for_monitor function guarantees that the monitor notices the
state change, we can skip the replication fixing which was somewhat
superficial in the first place.
The `MYSQL_ROW row` variable was being overwritten by the extra query done
by the SST method detection code. Moving it into its own function prevents
this and makes the code significantly easier to comprehend.
Added a test case that reproduced the problem (MaxScale crashed) and
verifies that the patch fixes the problem.
