GREG-232: Fixing wrong error message

iga/uib.py

@@ -20,7 +20,7 @@ class UibSebra(IgaImplementation):
     ) -> Optional[IgaPerson]:
         search = self.idtype_methodmap.get(id_type)
         if not search:
-            return []
+            return None
         user: User = search(extid)
         if not user:
             return None