Bump service-runner version to v2.2.5
Bump service-runner version to v2.2.5

The new service-runner, amongst other improvements, brings 5s DNS
caching, which allows us to easily re-route traffic to the other data
centre on the back-end without needing changes to Citoid's config.

Change-Id: I40c2d42eaabd14e300210c42dfa578c92829f71d

wikimedia/citoid,wikimedia/citoid,wikimedia/citoid