[Owncloud] Please exclude mediaplayer app for next release

[Bernhard Posselt]

We get a lot of issues for the mediaplayer which is currently 
unmaintained. That means that bugs wont be fixed and user satisfaction 
will be low.

I'd opt to exclude the app from the 5.0 release. If people really want 
this app, we will find a maintainer really quickly. Right now most 
people dont even know that this is unmaintained.