sshuttle autopkgtest failing in impish

[William Wilson]

The sshuttle autopkgtest is failing in impish with the currently released version of sshuttle:

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ERROR: setUpClass (__main__.SshuttleTest_xenial)
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Traceback (most recent call last):
  File "/tmp/autopkgtest.hCp3DV/build.X0T/src/debian/tests/cross-release", line 544, in setUpClass
    remote = Remote(f'remote-{cls.release}', cls.release)
  File "/tmp/autopkgtest.hCp3DV/build.X0T/src/debian/tests/cross-release", line 287, in __init__
    self._wait_for_networking()
  File "/tmp/autopkgtest.hCp3DV/build.X0T/src/debian/tests/cross-release", line 319, in _wait_for_networking
    raise Exception(f'Timed out waiting for remote {self.name} networking')
Exception: Timed out waiting for remote remote-xenial networking

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