1) The emonhub configuration for mqtt has both sub and pub - change the if statement at line 256 to allow this
2) Add tx/# to the mqtt subscribe at line 260
3) rf sendving via nodeval has 5 topic parts not 4, fix line 304 (see
   below)
4) Reinstate if statements:
 if topic_parts[0] == self._settings["nodevar_format_basetopic"][:-1]:
and
 if topic_parts[0] == self._settings["node_format_basetopic"][:-1]:
to avoid incorrect "Payload format error" messages

To transmit via MQTT, example for emonglcd:
topic:emonhub/tx/0/values/msg
payload:10,14,49,25,27,04,24,150,835,1600,502

Fix broken rf transmit behaviour in this version