Troubles with windows-1251 encoding detection.

[mkwork]

There is corresponding bug on gitlab's tracker: https://github.com/gitlabhq/gitlabhq/issues/5493.

My ruby skills are too pure to fix it graceful, but looks like bug in icu library, so best choice to use rchardet19. it's not based on icu. And, looks likes mozilla's engine detect encoding more accurately.