backfill data not filled properly due to wrong timezone info

[shlomiku]

when doing a backfill we get the data from alpaca/polygon at the beginning of the execution
then we change the tz info to match the NY tz
due to day light savings, we get an offset by M minutes (changes with the day and year)
how does it influence us?
e.g we need minute data from X to Y, but we get Y - M
M is the offset
so, backtrader doesn't "think" it has all the data it requires to start

we change replace() to localize() which takes care of the issue.
we could see the difference here:

you can read more about it here:
https://stackoverflow.com/a/1592837/2739124
https://stackoverflow.com/questions/35462876/python-pytz-timezone-function-returns-a-timezone-that-is-off-by-9-minutes
http://pytz.sourceforge.net/