Retry all API calls for >=500 responses

reraise original error otherwise.

Hardcoded 30 retries with 1 second interval.

Mostly useful to wake up the API dirung first cold start of Apache site
in the absence of haproxy probes.

Change-Id: I43dbc1f799913f010f87c73188be44fac07734fe
Related-Issue: PROD-32186
1 file changed