l10n: Updated Bulgarian translation of git (2257t,0f,0u)

Sync with tags v2.1.0-rc1 and v2.0.4

Signed-off-by: Alexander Shopov <ash@kambanaria.org>
Merge branch 'master' of github.com:alshopov/git-po

* 'master' of github.com:alshopov/git-po:
  l10n: Updated Bulgarian translation of git (2257t,0f,0u)