Improve wait-for-* execs

Right after start haproxy marks all backends as UP. It marks
problem ones as DOWN only after health-checks. So we should not
rely on BACKEND status while INI is in process.

Change-Id: Ia3743d446826ee1a9d42799a83e14a911a577966
Related-bug: #1391180
Merge "Improve wait-for-* execs"