Fix windows-1251 cyrillic encoding detection
Created by: XVilka
If try to see file with comments written in windows 1251 it shows crap. Hack-fixed in http://www.jackyfox.com/2012/10/31/gitlab-non-utf-8-russian-comments/ but 1) encode.rb is not in the tree 2) this is not proper fix, just dirty-dirty hack.