dump_update consider TRUE as boolean instead of stock symbol

[2young-2simple-sometimes-naive]

2021-03-16 19:43:33.280 | INFO | main:_dump_features:471 - dump bin errors： {'TRUE': 'concurrent.futures.process._RemoteTraceback: \n"""\nTraceback (most recent call last):\n File "/software/apps/python/3.7/lib/python3.7/concurrent/futures/process.py", line 232, in _process_worker\n r = call_item.fn(*call_item.args, **call_item.kwargs)\n File ".qlib/scripts/dump_bin.py", line 237, in _dump_bin\n code = fname_to_code(file_or_data.iloc[0][self.symbol_field_name].lower())\nAttributeError: 'bool' object has no attribute 'lower'\n"""\n\nThe above exception was the direct cause of the following exception:\n\nTraceback (most recent call last):\n File ".qlib/scripts/dump_bin.py", line 467, in _dump_features\n _future.result()\n File "/software/apps/python/3.7/lib/python3.7/concurrent/futures/_base.py", line 425, in result\n return self.__get_result()\n File "/software/apps/python/3.7/lib/python3.7/concurrent/futures/_base.py", line 384, in __get_result\n raise self._exception\nAttributeError: 'bool' object has no attribute 'lower'\n'}
2021-03-16 19:43:33.427 | INFO | main:_dump_features:473 - end of features dump.