initialise port as an empty dict rather than None

tes/tunnelstat/__init__.py

@@ -12,7 +12,7 @@ class SSHSession:
         self.last = datetime.datetime.now()
         self.socket = None
         self.token = None
-        self.port = None
+        self.port = {}
         self.key = ''
         self.cert = ''
         self.pids = []