Core/Unit: Don't apply liquid effects to game masters.

src/server/game/Entities/Unit/Unit.cpp

@@ -3139,7 +3139,8 @@ void Unit::ProcessTerrainStatusUpdate(ZLiquidStatus status, Optional<LiquidData>
     {
         if (_lastLiquid && _lastLiquid->SpellId)
             RemoveAurasDueToSpell(_lastLiquid->SpellId);
-        if (curLiquid && curLiquid->SpellId)
+        Player* player = GetCharmerOrOwnerPlayerOrPlayerItself();
+        if (curLiquid && curLiquid->SpellId && (!player || !player->IsGameMaster()))
             CastSpell(this, curLiquid->SpellId, true);
         _lastLiquid = curLiquid;
     }