umqtt.robust: Let reconnect() call the connect() method of parent class.

This allow overriding of the `connect()` method by a subclass, eg:

    from umqtt import robust

    class MQTTClient(robust.MQTTClient):
        def connect(self, clean_session=True):
            res = super().connect(clean_session)
            self.after_connect()
            return res

        def after_connect():
            # use for mqtt subscribe
            return

Author: puuu

micropython/umqtt.robust/umqtt/robust.py

@@ -20,7 +20,7 @@ def reconnect(self):
         i = 0
         while 1:
             try:
-                return super().connect(False)
+                return self.connect(False)
             except OSError as e:
                 self.log(True, e)
                 i += 1