[cli] set_last_update uniquement à la fin de supervise

pyheatpump/cli.py

     control_data = get_resp.json()
     if Heatpump(mac_address).control(control_data):
         logger.info('GET to supervisor succeded : updated values')
-        set_last_update(int(datetime.now().strftime('%s')))
     else:
         logger.warn('Unable to set data from supervisor\n{}'.format(control_data))
 
         logger.info('POST to supervisor failed')
 
     set_last_update(int(datetime.now().strftime('%s')))
-