fix for SH-4214: Crash on Linux readFromCache: ASSERT (mInitialized)

indra/newview/llappviewer.cpp

@@ -4974,6 +4974,7 @@ void LLAppViewer::disconnectViewer()
 	{
 		LLWorld::getInstance()->destroyClass();
 	}
+	LLVOCache::deleteSingleton();
 
 	// call all self-registered classes
 	LLDestroyClassList::instance().fireCallbacks();

indra/newview/llworld.cpp

@@ -123,7 +123,7 @@ void LLWorld::destroyClass()
 		LLViewerRegion* region_to_delete = *region_it++;
 		removeRegion(region_to_delete->getHost());
 	}
-	LLVOCache::deleteSingleton();
+	
 	LLViewerPartSim::getInstance()->destroyClass();
 
 	mDefaultWaterTexturep = NULL ;