am 624d5b4e: SIP: add DisconnectCause.SERVER_ERROR

Merge commit '624d5b4e8c20516516d0bff74479b9f5abdfe61c' into gingerbread-plus-aosp

* commit '624d5b4e8c20516516d0bff74479b9f5abdfe61c':
  SIP: add DisconnectCause.SERVER_ERROR