make sure the extraction would be skipped if there is empty list of animated_skeleton

openpype/hosts/maya/plugins/publish/extract_fbx_animation.py

@@ -42,6 +42,11 @@ class ExtractFBXAnimation(publish.Extractor):
         # Export from the rig's namespace so that the exported
         # FBX does not include the namespace but preserves the node
         # names as existing in the rig workfile
+        if not out_members:
+            self.log.debug(
+                "Top group of animated skeleton not found...skipping extraction")
+            return
+
         namespace = get_namespace(out_members[0])
         relative_out_members = [
             strip_namespace(node, namespace) for node in out_members