TradeCalendarManager: IndexError: index 4132 is out of bounds for axis 0 with size 4132

🐛 Bug Description

TradeCalendarManager: IndexError: index 4132 is out of bounds for axis 0 with size 4132

To Reproduce

Steps to reproduce the behavior:

1. The following code will raise the exception

start_time = "2021-01-01"

end_time = "2021-12-31"

calendar_manager = TradeCalendarManager("day", start_time, end_time)

for i in range(calendar_manager.get_trade_len()):

    trade_start_time, trade_end_time = calendar_manager.get_step_time(i)

    print(trade_start_time, trade_end_time, i, calendar_manager.start_index + i)

1. however, if you change the start_time and end_time to other values, it's fine. So I assume there must be a bug here.
   for examples:

start_time = "2017-01-01"
end_time = "2020-08-01"

Bug Exception

---------------------------------------------------------------------------
IndexError                                Traceback (most recent call last)
Input In [57], in <cell line: 13>()
     10 calendar_manager = TradeCalendarManager("day", start_time, end_time)
     13 for i in range(calendar_manager.get_trade_len()):
---> 14     trade_start_time, trade_end_time = calendar_manager.get_step_time(i)
     15     print(trade_start_time, trade_end_time, i, calendar_manager.start_index + i)

File ~/anaconda3/envs/py38/lib/python3.8/site-packages/qlib/backtest/utils.py:117, in TradeCalendarManager.get_step_time(self, trade_step, shift)
    115 trade_step = trade_step - shift
    116 calendar_index = self.start_index + trade_step
--> 117 return self._calendar[calendar_index], epsilon_change(self._calendar[calendar_index + 1])

IndexError: index 4132 is out of bounds for axis 0 with size 4132