[7523] Fixed: players will now drop flag in battleground if they cast immunity buff on themselves. Author: `win

TODO: players who carry flag in bg are imune to immunity buffs casted by friendly players. (todo added to code).
    Bug: if paladin casts Hand of protection on flag carrier - flag will be dropped, but he should get "target is immune" message.
    Fixed: Do not call Battleground::Update for battleground template objects.
    Fixed: Do not allow immune player to click on object in battleground (not sure if this is correct in all cases).

--HG--
branch : trunk

src/game/BattleGroundMgr.cpp

@@ -1178,7 +1178,7 @@ void BattleGroundMgr::Update(uint32 diff)
         // skip updating battleground template
         if( itr != m_BattleGrounds[i].end() )
             ++itr;
-        for(itr = m_BattleGrounds[i].begin(); itr != m_BattleGrounds[i].end(); itr = next)
+        for(; itr != m_BattleGrounds[i].end(); itr = next)
         {
             next = itr;
             ++next;