am 8d9e8de2: am 096df819: Merge "SipService: send SERVER_ERROR if server doesn\'t provide nonce" into gingerbread

Merge commit '8d9e8de2c920e8c9dc2da33410780ec739076bb9'

* commit '8d9e8de2c920e8c9dc2da33410780ec739076bb9':
  SipService: send SERVER_ERROR if server doesn't provide nonce