[Audacity-translation] Small improvement on German translation

[Laura-Marie H. <hen...@t-...>]

Hi there,

I noticed, while using Audacity in German, that there is a somewhat 
misleading translation of the word "interface" in the settings. 
Interface in English also means graphical interface, but when you use 
the same word for GUI and e.g. MIDI interface in the German translation, 
users cannot find the settings for the graphical interface.

So instead of translating (graphical) interface to "Schnittstelle", I 
would rather use "Oberfläche" (or "Benutzeroberfläche"), which is 
idiomatically more correct.

I attached the modified po file, which really only has this small 
correction. I hope I did it at the right line?

Have a nice week!

Kind regards
Laura Henning