fread converts `1` to `True` when reading certain csv files

- Did you find a bug in datatable, or maybe the bug found you?
fread convert 1 to True for certain csv file

- How to reproduce the bug?
I was working on the csv file 'debug.csv' which has lots of 1 in the first column. I noticed that when I read the file in datatable 0.10.1 by fread, it looks fine. But if I do the same thing using datatable 1.0.0, many '1' will be converted to 'True'.

[debug.csv](https://github.com/h2oai/datatable/files/7086166/debug.csv)
import datatable as dt
dt.fread('debug.csv')

- Your environment?
datatable 1.0.0, python 3.7.11, macOS BigSur 11.2.3