fix parsing of -0000 timezones

[anarcat]

This occurs namely on the XKCD feed available here:

https://www.xkcd.com/rss.xml

Fixes #402, fixes #548

[codecov]

Codecov Report

Merging #574 into master will decrease coverage by 2.36%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #574      +/-   ##
==========================================
- Coverage   95.12%   92.76%   -2.37%     
==========================================
  Files         302      302              
  Lines        2503     2502       -1     
==========================================
- Hits         2381     2321      -60     
- Misses        122      181      +59

Impacted Files	Coverage Δ
dateparser/timezones.py	100% <ø> (ø)	⬆️
dateparser/data/date_translation_data/nb.py	100% <ø> (ø)	⬆️
dateparser/parser.py	98.61% <ø> (+0.27%)	⬆️
dateparser/utils/strptime.py	92.68% <ø> (-7.32%)	⬇️
dateparser/languages/locale.py	98.39% <100%> (-0.27%)	⬇️
dateparser/freshness_date_parser.py	98.94% <100%> (ø)	⬆️
dateparser/calendars/hijri_parser.py	2.17% <0%> (-89.14%)	⬇️
dateparser/calendars/hijri.py	50% <0%> (-50%)	⬇️
dateparser/calendars/__init__.py	88.88% <0%> (-6.18%)	⬇️
... and 5 more

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[Gallaecio]

Nice catch!

[seanthegeek]

Out of curiosity, why hasn't this been merged yet?

[noviluni]

Thank you @anarcat !