security: Do not let grpc reload ssh cert if not changed (#9068) (#9069)

[windtalker]

ref #8535

What problem does this PR solve?

Issue Number: close #xxx

Problem Summary:

What is changed and how it works?

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

None

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: gengliqi, zanmato1984

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-05-23 06:58:44.186796431 +0000 UTC m=+2327677.943932004: ☑️ agreed by gengliqi.
• 2024-05-23 07:10:29.437424057 +0000 UTC m=+2328383.194559833: ☑️ agreed by zanmato1984.