Retry requests also on ESOCKETTIMEOUT

Request module sets two timeouts:
- timeout for the whole request (fails with ETIMEOUT, handled by wd)
- socket timeout, used when response received header but failed to
  receive data. This one fails with ESOCKETTIMEOUT and not handled
  by wd, so retries does not occur for it.
Merge pull request #326 from SevInf/fix/esockettimedout

Retry requests also on ESOCKETTIMEOUT