Don't suggest the user specify -Dhpss

While trying to push to launchpad, something went wrong, and part of the message generated by bzr was:

No supported authentication methods left to try!
bzr: ERROR: Connection closed: please check connectivity and permissions (and try -Dhpss if further
diagnosis is required)

Its not clear to a casual user what '-Dhpss' does - and indeed, after specifying it, the behaviour doesn't seem to change at all - you still get the identical output, including a suggestion to add that switch (even though it already is). That flag did cause more output to be written to the log, but that isn't clear (and the additional output generated is no use for a user to diagnose this)

Martin suggested I open a bug on this issue: we should never inform the user to try debugging flags as a matter of course - it has the potential to confuse them, and without telling them what do do *after* they have specified the option they will remain lost.

The message comes from:
  File "D:\src\bazaar\bzr.dev\bzrlib\smart\message.py", line 258, in read_response_tuple
    self._wait_for_response_args()
  File "D:\src\bazaar\bzr.dev\bzrlib\smart\message.py", line 224, in _wait_for_response_args
    self._read_more()
  File "D:\src\bazaar\bzr.dev\bzrlib\smart\message.py", line 247, in _read_more
    "(and try -Dhpss if further diagnosis is required)")
ConnectionReset: Connection closed: please check connectivity and permissions (and try -Dhpss if further diagnosis is required)