We couldn't install all our dependencies because of conflicting
versions:

```
The following packages have unmet dependencies:
libgd-dev : Depends: libgd3 (= 2.2.5-5.2ubuntu2.1)
  but 2.3.3-9+ubuntu20.04.1+deb.sury.org+1 is to be installed
```

This is actually unrelated. I mixed up roles while updating a dependency
but it doesn't hurt to stay up-to-date. So I keep this commit in.

Hopefully the new version will create postgres users with the defined
permission to create databases.

Since we are importing only parts of another role, we missed to include
this new part after some update. This should give the database user the
permission to create its database again.