Problem: the test set @@global.init_slave to garbage at a time
which was not guaranteed to be after the time when the slave's
SQL thread used it. That would cause the slave's SQL thread to
stop in rare cases.
Fix: The test does not care about the value of
@@global.init_slave, except that it should be different on
master and slave. Hence, we set @@global.init_slave to
something that is valid SQL.


mysql-test/suite/rpl/r/rpl_variables.result:
  updated result file.
mysql-test/suite/rpl/t/rpl_variables.test:
  Set @@global.init_slave to something that is valid SQL.