Merge pull request #55 from ppv1979/ojs-stable-2_4

Fully Revised Russian Translation
*8254* Moved notify admin functionality to scheduled task class
*8015* Only retry request if the curl execution response is false (avoid reposting when request is successful but the response is empty)
*8491* Introduced option to avoid cleaning request response
Update Russian translation after *8254*

Change ru_RU locale after changing locale en_US in *8254*