Change listen address to 127.0.0.1

tests/sshserver.py

@@ -81,7 +81,7 @@ def run_ssh_server(app):
     # now connect
     sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
     sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
-    sock.bind(('', 2200))
+    sock.bind(('127.0.0.1', 2200))
     sock.listen(100)
 
     while not app._tear_down: