recoverd: If obtaining recovery lock fails, try again

recoverd: If obtaining recovery lock fails, try again

When ctdb daemon starts up, it considers itself the recovery master
and tries to do first recovery.  However, it's possible that there is
already a recovery master and the current node has not yet heard from it.
So do not ban ourselves immediately if ctdb_recovery_lock() fails when
doing first recovery.

Signed-off-by: Amitay Isaacs <amitay@gmail.com>
Reviewed-by: Martin Schwenke <martin@meltin.net>
(Imported from commit 57310f80c9b8146a0978d912f73b0a64fde7697e)