net/py-paho-mqtt: Update to 1.6.1

Upstream changes:

1.6.1:
  fix python27, broken in 1.6.0

1.6.0:

  - Big performance improvement when receiving large payloads,
  particularly for SSL. Closes #571,
  - Add basic MQTT v5 support to the subscribe and publish helper
  functions. Closes #575.
  - Changed default TLS version to 1.2 instead of 1.0.
  - Remove _out_packet_mutex and _current_out_packet_mutex and convert
  the _out_packet queue use to thread safe (simplifies the internals)
  - Callbacks can now be applied to client instances using decorators.
  - The `rc` parameter in the `on_disconnect` callback now has
  meaningful values in the case of an error. Closes #441.
  - Remove periodic retry checks for outgoing messages with QoS>0. This
  means that outgoing messages will only be retried on the client
  reconnecting to the server. They will *not* be retried when the client
  is still connected.
  - MQTTMessageInfo.wait_for_publish() and
  MQTTMessageInfo.is_published() will now raise exceptions if called
  when the publish call produced an error. Closes #550.
  - Raise exceptions when attempting to set MQTT v5 properties to
  forbidden values. Closes #586.
  - PUBACK messages are now sent to the broker only after the on_message
  callback has - Add timeout to
  MQTTMessageInfo:wait_for_publish().returned.
  - Add timeout to MQTTMessageInfo:wait_for_publish().
  - Removed ancient Mosquitto compatibility class.

  bugfixes


(gdt)