[Client] Don't clear container Ptrs when disposing of corpses

The reason for this is that only the server should be determine whether a corpse can be disposed of or not.

apps/openmw/mwgui/container.cpp

@@ -391,8 +391,6 @@ namespace MWGui
             /*
                 End of tes3mp change (major)
             */
-
-            mPtr = MWWorld::Ptr();
         }
     }