fix: ignore hash if local secret is unset

[sweatybridge]

What kind of change does this PR introduce?

Bug fix

What is the new behavior?

If local secret is unset, no need to diff with platform defaults.

Additional context

Add any other context or screenshots.

[coveralls]

Pull Request Test Coverage Report for Build 12595422178

Details

• 19 of 30 (63.33%) changed or added relevant lines in 1 file are covered.
• 8 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.06%) to 59.673%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pkg/config/auth.go	19	30	63.33%

Files with Coverage Reduction	New Missed Lines	%
internal/debug/postgres.go	3	64.86%
internal/gen/keys/keys.go	5	12.9%

Totals
Change from base Build 12593707873:	-0.06%
Covered Lines:	7665
Relevant Lines:	12845

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💛 - Coveralls