Added product_id which is missing

git-svn-id: https://redmine.imt-atlantique.fr/svn/xaal/code/Python/branches/0.7@3028 b32b6428-25c9-4566-ad07-03861ab6144f

devices/protocols/Yeelight/xaal/yeelight/devices.py

@@ -101,6 +101,9 @@ class YeelightDev(object):
     def _update_properties(self):
         properties = self.bulb.get_properties()
         self.on_properties(properties)
+        # we need to be connected to find out which model
+        if self.dev.product_id == None:
+            self.dev.product_id = self.bulb.bulb_type
 
 
 class RGBW(YeelightDev):