Serbian translation. Fixes #1907
remove sr-cyrl, it's the same as sr
rearanged language array
Merge branch '1907-sr-language' of https://github.com/johonunu/yii2 into johonunu-1907-sr-language

* '1907-sr-language' of https://github.com/johonunu/yii2:
  rearanged language array
  remove sr-cyrl, it's the same as sr
  Serbian translation. Fixes #1907

Conflicts:
	framework/messages/config.php