contint: Icinga now notify on contint related stuff

Commit 5b2ed161cc added an Icinga contact group 'contint' which we can
use to notify on jenkins/zuul issues (RT #6966).

Adding the contact group for:
- zuul process
- zuul gearman daemon
- jenkins process

Change-Id: I12fe316808c4b60d420bee0a0683ce82cb10e3f3
Merge "contint: Icinga now notify on contint related stuff" into production