fix sync_metadata peer sort

oml/item/models.py

@@ -325,8 +325,11 @@ class Item(db.Model):
         if self.meta.get('sharemetadata'):
             return
         peers = [u for u in self.users if u.id != settings.USER_ID]
-        peers.sort(key=lambda u: ox.sort_string(str(u.info.get('index', ''))
-            + 'Z' + (u.info.get('name') or '')))
+        def peer_sort(u):
+            info = u.json()
+            return ox.sort_string(str(info.get('index', ''))
+                                  + 'Z' + (info.get('name') or ''))
+        peers.sort(key=peer_sort)
         sync_from = None
         first_peer = None
         # get first peer with sharemetadata set