Updated mediawiki/extensions
Project: mediawiki/extensions/BetaFeatures  a13e67739058697d9ca608029a3bfd42fc123aef

betafeatures.css: Remove Sass compilation artifacts

The source files aren't even available anywhere, as far as I know,
and this file has been edited directly already.

Change-Id: I1993d0f1507f89f5a7e2ff4f0048d0f53775f1d5