Making the `gettext:updated_check` by completely regenerating the gitlab.pot.

This avoids an issue where `gettext:find` would not pick up on changes
if the file isn't removed first.

Since we are only using `.po` files for translation we can shave off
some setup time.

Generating the `mo` files also regenerates the PO-files, including
fuzzy translations. Those cause a lot of bugs, and we don't need them
anymore since the `po` files are generated by an external translation service.

This makes the output in static analysis a bit more verbose.

That way we don't need to install it in production, since it's really
not needed there.