[tools] Fixed infinite loop in config scan due to list comparison error

Previously a scanning for config terminated on comparison of the feature
set, however at some point the set was changed to a list. This resulted
in non-deterministic failures based on list order.

Author: geky

tools/config.py

@@ -444,7 +444,7 @@ def load_resources(self, resources):
             self.add_config_files(resources.json_files)
 
             # Add features while we find new ones
-            features = self.get_features()
+            features = set(self.get_features())
             if features == prev_features:
                 break