Updated the getattr patch

ontopy/patch.py

@@ -29,6 +29,7 @@
 # Extending ThingClass (classes)
 # ==============================
 
+# Save a copy of the unpatched ThingClass.__getattr__() method.
 save_getattr = ThingClass.__getattr__
 
 
@@ -133,7 +134,13 @@
             entity = self.namespace.ontology.get_by_label(name)
             # add annotation property to world._props for faster access later
             self.namespace.world._props[name] = entity
-            return save_getattr(self, entity.name)
+
+            # Try first unpatched getattr method to avoid risking
+            # infinite recursion.
+            try:
+                return save_getattr(self, entity.name)
+            except AttributeError:
+                return getattr(self, entity.name)
         raise err