Comment 6 for bug 1063087

This introduces a warning in the testsuite for me:

======================================================================
ERROR: test_send_remove_branch (dulwich.tests.compat.test_client.DulwichTCPClientTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "dulwich/tests/compat/test_client.py", line 216, in test_send_remove_branch
    c.send_pack(self._build_path('/dest'), lambda _: sendrefs, gen_pack)
  File "dulwich/client.py", line 485, in send_pack
    progress)
  File "dulwich/client.py", line 322, in _handle_receive_pack_tail
    self._read_side_band64k_data(proto, channel_callbacks)
  File "dulwich/client.py", line 266, in _read_side_band64k_data
    for pkt in proto.read_pkt_seq():
  File "dulwich/protocol.py", line 147, in read_pkt_seq
    pkt = self.read_pkt_line()
  File "dulwich/protocol.py", line 113, in read_pkt_line
    raise GitProtocolError(e)
GitProtocolError: [Errno 104] Connection reset by peer

----------------------------------------------------------------------