git-gui: update Russian translation

Translation is done on Transifex: https://www.transifex.com/djm00n/git-po-ru/git-gui/
If you have any corrections please report them there.

Signed-off-by: Dimitriy Ryazantcev <[email protected]>
Signed-off-by: Pratyush Yadav <[email protected]>

Author: DJm00n