ICARUSservices.py: fix access to class variables

Co-authored-by: Copilot Autofix powered by AI <[email protected]>

Author: PetrilloAtWork

icarusalg/gallery/helpers/python/ICARUSservices.py

@@ -92,7 +92,7 @@ def defaultConfiguration(self):
     `configPath` is included directly, and it is assumed that it already
     properly defines a `services` table.
     """
-    return DefaultConfigPath, DefaultServiceTable
+    return self.DefaultConfigPath, self.DefaultServiceTable
   # defaultConfiguration()
 
   def __init__(self):