set broadphase handle to zero when destructing a btCollisionWorld, just in case a collision object/ rigid body is re-used.

Thanks to Ole for reporting

Fix a bug , causing some deep penetrations to be missed. Not likely to have impacted many users, as such deep penetrations should have prevented in the first place.
Thanks a lot to Andy O'Neil for reporting and reproduction case.

src/BulletCollision/CollisionDispatch/btCollisionWorld.cpp

@@ -69,6 +69,7 @@ btCollisionWorld::~btCollisionWorld()
 			//
 			getBroadphase()->getOverlappingPairCache()->cleanProxyFromPairs(bp,m_dispatcher1);
 			getBroadphase()->destroyProxy(bp,m_dispatcher1);
+			collisionObject->setBroadphaseHandle(0);
 		}
 	}