Fix set_hsv whe, light is off

git-svn-id: https://redmine.imt-atlantique.fr/svn/xaal/code/Python/branches/0.7@2940 b32b6428-25c9-4566-ad07-03861ab6144f

devices/protocols/Meross/xaal/meross/bindings.py

@@ -88,6 +88,11 @@ class RGBLamp(MerossDev):
             hsv = _hsv
         h,s,v = hsv
         rgb=tuple(round(i * 255) for i in colorsys.hsv_to_rgb(h/360.0,s,v))
+        # meross API fail to detect when light is off and set_light_color() is called
+        # set_light_color() will turn light on but the API think it is still off
+        # so turn it on first
+        if self.embs[0].attributes['light'] == False:
+            await self.meross.async_turn_on()
         await self.meross.async_set_light_color(rgb=rgb)
         await self.update()
         self.embs[0].attributes['mode'] = 'color'