fix: timezone offset with old pytz and pandas

It seems that older pandas and pytz distributions (for example, ones
from Debian 10 deb repositories) are prone to issues when pytz timezone
offset ignores current datetime value [1]. Using explicit localize is
both valid in modern version and fixes the bug for older ones.

1. https://stackoverflow.com/questions/11473721/weird-timezone-issue-with-pytz

Part of #198

Author: DifferentialOrange

Diff for: CHANGELOG.md

@@ -211,6 +211,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Puting test files in pip package (#238).
 - Make connection close idempotent (#250).
 - readthedocs version (#255).
+- timezone offset with old pytz and pandas (#198).
 
 ## 0.9.0 - 2022-06-20
 

Diff for: Makefile

@@ -64,7 +64,7 @@ rpm-dist-check:
 
 .PHONY: deb-changelog-entry
 deb-changelog-entry:
-	[email protected] dch --distribution unstable \
+	[email protected] dch --distribution unstable -b \
 									 --package "python3-tarantool" \
 									 --newversion $$(python3 setup.py --version) \
 									 "Nightly build"

Diff for: tarantool/msgpack_ext/types/datetime.py

@@ -291,9 +291,9 @@ def __init__(self, *, timestamp=None, year=None, month=None,
                 datetime = pandas.to_datetime(timestamp, unit='s')
 
             if not timestamp_since_utc_epoch:
-                self._datetime = datetime.replace(tzinfo=tzinfo)
+                self._datetime = datetime.tz_localize(tzinfo)
             else:
-                self._datetime = datetime.replace(tzinfo=pytz.UTC).tz_convert(tzinfo)
+                self._datetime = datetime.tz_localize(pytz.UTC).tz_convert(tzinfo)
         else:
             if nsec is not None:
                 microsecond = nsec // NSEC_IN_MKSEC
@@ -306,7 +306,7 @@ def __init__(self, *, timestamp=None, year=None, month=None,
                 year=year, month=month, day=day,
                 hour=hour, minute=minute, second=sec,
                 microsecond=microsecond,
-                nanosecond=nanosecond, tzinfo=tzinfo)
+                nanosecond=nanosecond).tz_localize(tzinfo)
 
     def _interval_operation(self, other, sign=1):
         """