RtContentsITCase.java:263-264: unignore after...

The puzzle `863-4e783bd3` from #863 has to be resolved:

https://github.com/jcabi/jcabi-github/blob/5c55c3b06922e67860702945eb86e02d7b5f09ef/src/test/java/com/jcabi/github/RtContentsITCase.java#L263-L264

The puzzle was created by maurezen on 22-Jan-15.

Estimate: 30 minutes,

If you have any technical questions, don't ask me, submit new tickets instead. The task will be \"done\" when the problem is fixed and the text of the puzzle is _removed_ from the source code. Here is more about [PDD](http://www.yegor256.com/2009/03/04/pdd.html) and [about me](http://www.yegor256.com/2017/04/05/pdd-in-action.html).