fix(controller): Use correct entrypoint for run

Running commands in an image build using git push requires to use ‘/runner/init’ as entrypoint, otherwise environment variables inject by buildpacks are missing.

Fixes #1801, fixes #1568
I think this can be optimized into a one-liner:

```
l.update({'entrypoint': kwargs.get('entrypoint')}) if kwargs.get('entrypoint')
```