Add check for str type of stat_key

src/login.py

@@ -164,7 +164,7 @@ def get_stat_overrides() -> dict[int, dict[str, dict[str, float]]]:
             if player_id not in stat_overrides_map[week]:
                 stat_overrides_map[week][player_id] = {}
             for row in df_player.itertuples():
-                if row.stat_key and row.stat_value:
+                if isinstance(row.stat_key, str) and row.stat_value:
                     stat_overrides_map[week][player_id][row.stat_key] = float(row.stat_value)
 
     return stat_overrides_map