Less dependent on input sequnece, use template length instead

openfold/data/templates.py

@@ -975,7 +975,7 @@ def get_custom_template_features(
         )
         # chain_id defaults to A, should be changed?
         template_sequence = mmcif_parse_result.mmcif_object.chain_to_seqres[chain_id]
-        mapping = {x: x for x, _ in enumerate(query_sequence)}
+        mapping = {x: x for x, _ in enumerate(template_sequence)}
 
         curr_features, curr_warnings = _extract_template_features(
             mmcif_object=mmcif_parse_result.mmcif_object,