Some of the older tests expected results that didn't make much sense. The
mxs1643_extra_events test should expect the master to devolve into the
Running state when it is set into read-only. This is understandable as a
set of servers consisting only of slaves is rather disorienting.
In mxs1678_relay_master breaking the replication of the relay master
devolves it into the Running state as well as all slaves replicating from
it. This is a better result as in a real-life scenario only the valid and
up-to-date slaves would be used.
Don't test failover functionality when it is not needed. The bug is only
about the extra events that appear when a master is demoted and a slave is
promoted.
