Fix test.py

git-svn-id: https://redmine.imt-atlantique.fr/svn/xaal/code/Python/branches/0.7@2646 b32b6428-25c9-4566-ad07-03861ab6144f

devices/DummyDevices/lamp.py

@@ -24,7 +24,7 @@ def main(addr):
         light.value = False
         print("%s OFF" %dev)
     
-    def dim(_brightness,_smooth):
+    def dim(_brightness,_smooth=None):
         # this device doesn't support _smooth parameter
         val = int(_brightness)
         if (val <= 100) and (val >=0):