Avoid facts gathered twice when deploying with --limit
Avoid facts gathered twice when deploying with --limit

When deploying with argument --limit, both first and second plays
in site.yml will be processed, causing host facts gathered twice,
which is unnecessary. Thus a condition is added to the first play
to avoid such redundancy.

Change-Id: I20b84c59bf73aaeca929fc56465ff2cf1cf52b8e
Closes-Bug: #1691033

dardelean/kolla-ansible,dardelean/kolla-ansible,dardelean/kolla-ansible