Replace World::getConfig with World::getFloatConfig, World::getIntConfig, and World::getBoolConfig.

Also fix a warning from a previous commit.

--HG--
branch : trunk

src/server/game/Entities/GameObject/GameObject.cpp

@@ -519,7 +519,7 @@ void GameObject::Update(uint32 diff)
             m_respawnTime = time(NULL) + m_respawnDelayTime;
 
             // if option not set then object will be saved at grid unload
-            if (sWorld.getConfig(CONFIG_SAVE_RESPAWN_TIME_IMMEDIATELY))
+            if (sWorld.getBoolConfig(CONFIG_SAVE_RESPAWN_TIME_IMMEDIATELY))
                 SaveRespawnTime();
 
             UpdateObjectVisibility();