Make access to ObjectMgr´s creature and gobject respawntime storage threadsafe.

(TODO: Maybe this should be stored on map level instead)
Fixes issue #3006
Fixes issue #3071

--HG--
branch : trunk

src/server/game/Globals/ObjectMgr.h

@@ -1084,7 +1084,9 @@ class ObjectMgr
         GossipMenuItemsLocaleMap mGossipMenuItemsLocaleMap;
         PointOfInterestLocaleMap mPointOfInterestLocaleMap;
         RespawnTimes mCreatureRespawnTimes;
+        ACE_Thread_Mutex m_CreatureRespawnTimesMtx;
         RespawnTimes mGORespawnTimes;
+        ACE_Thread_Mutex m_GORespawnTimesMtx;
 
         CacheNpcTextIdMap m_mCacheNpcTextIdMap;
         CacheVendorItemMap m_mCacheVendorItemMap;