always init mac in config module

pyheatpump/config.py

@@ -52,6 +52,8 @@ config.read(filenames=CONFIG_FILES)
 API_HOST=config.get('api', 'host')
 API_PORT=config.get('api', 'port')
 
+mac_address_init()
+
 def save_config():
     with open(CONFIG_FILES[-1], 'w') as conf_file:
         config.write(conf_file)