--- a/util/misc.py	Mon Feb 12 13:18:53 2018 +0100
+++ b/util/misc.py	Tue Feb 13 13:57:53 2018 +0100
@@ -59,13 +59,8 @@
             mod = __import__(param.rsplit('.', 1)[0])
             return reduce(getattr, param.split('.')[1:], mod)
         return factory
-    elif isinstance(param,types.ClassType):
+    else:
         return lambda : param
-    else:
-        # backward compatibility 
-        # for old extensions that pass some callables
-        # deprecated, should not be used anymore
-        return param
 
 
 def InstallLocalRessources(CWD):