Make test_autopack_rpc_is_used_when_using_hpss raise KnowFailure for CHK repos.
* bzrlib/tests/test_pack_repository.py:
(TestSmartServerAutopack.test_autopack_rpc_is_used_when_using_hpss):
InterPackToRemotePack explicitely avoid using the autopack RPC,
let's try again once fetching has been improved.