Don't attempt to check if varnishd is still running if we have already failed.
Don't attempt to check if varnishd is still running if we have
already failed.

Fixes #2301

gquintard/Varnish-Cache,feld/Varnish-Cache,gquintard/Varnish-Cache,feld/Varnish-Cache,gquintard/Varnish-Cache,feld/Varnish-Cache,feld/Varnish-Cache,gquintard/Varnish-Cache,feld/Varnish-Cache