TestLocationMatcher.test_file_urls_are_normalized failure on windows

[Vincent Ladeuil]

Traceback (most recent call last):
  File "\\VBOXSRV\babune\lib\python\testtools\runtest.py", line 144, in _run_user
    return fn(*args)
  File "\\VBOXSRV\babune\lib\python\testtools\testcase.py", line 487, in _run_test_method
    testMethod()
  File "c:\cygwin\home\babune\babune\slaves\xp-32bits.local\workspace\selftest-windows\bzrlib\tests\test_config.py", line 2203, in test_file_urls_are_normalized
    matcher = config.LocationMatcher(store, 'file:///dir/subdir')
  File "c:\cygwin\home\babune\babune\slaves\xp-32bits.local\workspace\selftest-windows\bzrlib\config.py", line 2413, in __init__
    location = urlutils.local_path_from_url(location)
  File "c:\cygwin\home\babune\babune\slaves\xp-32bits.local\workspace\selftest-windows\bzrlib\urlutils.py", line 232, in _win32_local_path_from_url
    raise errors.InvalidURL(url, 'Win32 file urls start with'
InvalidURL: Invalid url supplied to transport: "file:///dir/subdir": Win32 file urls start with file:///x:/, where x is a valid drive letter

probably shallow.