Fix silence_exceptions tuple and comparison against missing update date

[GriffTanen]

Two small, unrelated bugs found while looking at something else.

1. silence_exceptions is always truthy

src/torrt/utils.py:

self.silence_exceptions = silence_exceptions,   # note the trailing comma

The trailing comma makes this a tuple, so HttpClient(silence_exceptions=False)
stores (False,), which is truthy. As a result raise_on_error_response = True
— set by tests/trackers/* precisely to make request errors visible — has no
effect, and failures stay swallowed.

>>> HttpClient(silence_exceptions=False).silence_exceptions
(False,)

Removing the comma restores the intended behaviour. I ran the tracker tests
afterwards to check that unmasking errors does not surface new failures — it
does not; they still pass.

2. TypeError when a tracker reports no update date

src/torrt/base_tracker.py:

if last_updated and last_updated >= page_data.date_updated:

extract_page_date_updated() returns None by default, and both the kinozal and
nnmclub implementations also return None when the date cannot be parsed. Once a
torrent has a stored date_updated, the next walk raises:

TypeError: '>=' not supported between instances of 'datetime.datetime' and 'NoneType'

Guarding the comparison keeps the previous behaviour for the no-date case: we do
not skip, we go and fetch.

🤖 Generated with Claude Code

[coveralls]

Coverage Report for CI Build 33317791939

Coverage increased (+0.02%) to 67.991%

Details

• Coverage increased (+0.02%) from the base build.
• Patch coverage: 3 of 3 lines across 2 files are fully covered (100%).
• No coverage regressions found.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

No coverage regressions found.

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Coverage Stats

Relevant Lines:	1687
Covered Lines:	1147
Line Coverage:	67.99%
Coverage Strength:	3.87 hits per line

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💛 - Coveralls

[idlesign]

Thank you. Merged.