Fix haproxy backend checks dependencies

Openstack::Ha::Haproxy_service['keystone*']
should always be evaluated *before* any
Exec['wait-for-keystone*'] backend checks.

Closes-bug: #1352964

Change-Id: I579f33d673925bea27ceab48f3380ed1dda40170
Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
Merge "Fix haproxy backend checks dependencies"