FinRL_PaperTrading_Demo np.hstack()

When executing the example [here](https://github.com/AI4Finance-Foundation/FinRL-Meta/blob/master/examples/FinRL_PaperTrading_Demo.ipynb) without any modifications except for including Alpaca API key, I get the following error:

> ValueError: all the input array dimensions for the concatenation axis must match exactly, but along dimension 0, the array at index 0 has size 1192 and the array at index 1 has size 1177

which is coming from this line [here](https://github.com/AI4Finance-Foundation/FinRL/blob/0ade291503e031fc2013d462554f14c9e8817c5c/finrl/meta/data_processors/processor_alpaca.py#L267). Anyone else run into this issue?