Builder: wrong reference string for several (most) languages

[frhun <s frhun de>]

I already tired to patch it myself here: 
https://gitlab.gnome.org/GNOME/gnome-builder/merge_requests/236#note_668726

but i got turned down for not going through the official translation 
channel. Now this is not a "real" translation issue as it really is only 
a changed reference string that has to be changed for every language. 
(and hopefully not individually)

Some languages already fixed the issue(s), but these didn't:

ca, cs, da, de, el, en_GB, es, eu, fi, fr, gl, id, it, kk, ko, lt, nl, 
pl, pt_BR, ro, ru, sl, sr, sv, tr