fix custom-formats with timezone

[noviluni]

Fix ValueError when parsing a date string that already contains timezone info with the custom-formats parser.

fixes: #376, closes: #375

[codecov]

Codecov Report

Merging #840 (b3ab812) into master (939e722) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #840   +/-   ##
=======================================
  Coverage   98.33%   98.34%           
=======================================
  Files         231      231           
  Lines        2590     2594    +4     
=======================================
+ Hits         2547     2551    +4     
  Misses         43       43           

Impacted Files	Coverage Δ
dateparser/utils/__init__.py	96.18% <100.00%> (+0.12%)	⬆️

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[Gallaecio]

💄

Suggested change

	if (
	not settings.RETURN_AS_TIMEZONE_AWARE
	or (settings.RETURN_AS_TIMEZONE_AWARE
	and 'default' == settings.RETURN_AS_TIMEZONE_AWARE and not is_originally_aware)
	):
	if (
	not settings.RETURN_AS_TIMEZONE_AWARE
	or (
	not is_originally_aware
	and settings.RETURN_AS_TIMEZONE_AWARE == 'default'
	)
	):

[Gallaecio]

💄 is_tz_aware or has_tz?

[Gallaecio]

Are these tests complete enough?

Given the changes I would expect a test where the date contains a timezone, settings specify a different timezone, and we check that the parsed timezone is the one from the input string, and not the one from the settings.

Also a test about the change to if settings.RETURN_AS_TIMEZONE_AWARE is not True:.