Catch spurious exceptions (python-2.6) when SocketServer is shut down.
* bzrlib/tests/test_http.py: (TestProxyHttpServer.proxied_in_env, TestProxyHttpServer.not_proxied_in_env): Revert expected and actual expressions to conform with bzr rules.
* bzrlib/tests/http_server.py: (HttpServer.__repr__): Added for debug purposes. (HttpServer._http_start): Catch spurious exceptions when running with python-2.6.