Fixed SA_DISPELL failing outside GvG against party

- Follow-up to a4802eae
- Fixes bugreport #7572 - special thanks to kyeme
  http://hercules.ws/board/tracker/issue-7572-dispell-2
- SA_DISPELL would fail if two players outside PvP grounds are in the
  same party AND in the same guild at the same time.

Signed-off-by: Haru <haru@dotalux.com>