WebHost: Fix internal server error if hint field is empty

WebHostLib/tracker.py

@@ -269,6 +269,7 @@ def get_tracker(tracker: UUID):
                    for teamnumber, team in enumerate(names)}
     precollected_items = room.seed.multidata.get("precollected_items", None)
     hints = {team: set() for team in range(len(names))}
+    if "hints" in room.multisave:
         for key, hintdata in room.multisave["hints"]:
             for hint in hintdata:
                 hints[key[0]].add(Hint(*hint))