[airos] fixed config attribute for class airos converter

Author: edoput

netjsonconfig/backends/airos/converters.py

@@ -31,7 +31,7 @@ def should_run_forward(cls, config):
 
     @property
     def netmode(self):
-        return self.config.get('netmode', 'bridge')
+        return self.netjson.get('netmode', 'bridge')
 
 
 class Aaa(AirOsConverter):