[SSSD] [sssd PR#12] failover: proceed normally when no new server is found (opened)

[fidencio]

pbrezina's pull request #12: "failover: proceed normally when no new server is found" was opened

PR body:
"""
https://fedorahosted.org/sssd/ticket/3131

I couldn't reproduce manually so I used the second patch as a by-code reproducer. If you apply the patch then sssd will try to resolve meta server twice simultaneously and triggering the problematic code path. You can search for RESOLV SRV DONE in logs.
"""

See the full pull-request at https://github.com/SSSD/sssd/pull/12
... or pull the PR as Git branch:
git remote add ghsssd https://github.com/SSSD/sssd
git fetch ghsssd pull/12/head:pr12
git checkout pr12