Revert "gnustep: remove it from moonbase." grrrrr

This reverts commit b27d86b49af9ad855addf602281319ed6792084e.

Guide for removing modules
~~~
1. check (using e.g. `git log .`) when and by whom it was last updated
-> if this is not too long ago or you know the last editor _write him a mail_

2. check if anything in the moonbase still depends on it(`lvu leert <module>`)
-> if it does, check if these can be removed as well

3. if both checks fail, THEN _THINK_ about removing it.

Florin, you failed at all three steps and even ignored my request to revert
it. WHAT THE HACK.