Fixed SA_DISPELL failing outside PvP against party

- Follow-up to a4802eae
- Fixes bugreport #7572
  http://hercules.ws/board/tracker/issue-7572-dispell-2
- SA_DISPELL would fail outside PvP if caster and target are in the same
  party AND in the same guild at the same time.
- Special thanks for kyeme (bugreport), Xgear (review.)

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