Don't use --command in tests; use command.


mysql-test/r/rpl_until.result:
  result update
mysql-test/t/rpl_until.test:
  real-sleep is incorrect syntax; mysqltest knows only real_sleep.
  Tip: don't use -- before commands; if mysqltest does not recognize the command
  after -- it just says "it must be a comment", so there is no syntax error detection.
  If you don't use the -- it will report the syntax error.
  The typo caused no sleep, so the slave did not have time to stop.
  Now it has time so we needn't replace the Slave_SQL_Running
  (and it's better to not replace it, because if we don't see that it
  is running, it will trigger errors just a bit later).