Tunnel tests break on Windows when squid is present

[Manuel de la Peña]

u1-dev-tools supports proxy tests on windows, when squid is installed (and therefore squid tests are ran) the following happens:

  TunnelClientTestCase
    test_connects_right ... Traceback (most recent call last):
Failure: twisted.internet.error.ConnectError: An error occurred while connecting
: 10049: The requested address is not valid in its context..
[ERROR]
    test_starts_tls_connection ... Traceback (most recent call last):
Failure: twisted.internet.error.ConnectError: An error occurred while connecting
: 10049: The requested address is not valid in its context..
[ERROR]
tests.proxy.test_tunnel_server
  AnonProxyRemoteSocketTestCase
    test_client_read ... Traceback (most recent call last):
Failure: twisted.internet.defer.TimeoutError: <tests.proxy.test_tunnel_server.An
onProxyRemoteSocketTestCase testMethod=test_client_read> (test_client_read) stil
l running at 3.0 secs
[ERROR]
QObject::startTimer: QTimer can only be used with threads started with QThread