Empty git commit to overcome docker limitation

```
Preparing environment
exec /usr/bin/dumb-init: argument list too long
ERROR: Job failed: prepare environment: exit code 1. Check https://docs.gitlab.com/runner/shells/index.html#shell-profile-loading

 for more information
```

Signed-off-by: Ritesh Raj Sarraf <ritesh.sarraf@collabora.com>