Dont try to set attributes on cfg in setConfiguration if we're trying to clear...

Dont try to set attributes on cfg in setConfiguration if we're trying to clear the configuration by passing it None.

lib/python/App/config.py

@@ -41,6 +41,9 @@ def setConfiguration(cfg):
     global _config
     _config = cfg
 
+    if cfg is None:
+        return
+	
     from App import FindHomes
     import __builtin__
     __builtin__.CLIENT_HOME = FindHomes.CLIENT_HOME = cfg.clienthome