fix(plugins/acme): fix certificate renew failure issue

[Water-Melon]

Summary

Fix ACME renewal bug.

Using client.renew_certificate directly as the callback function in ngx_timer_at causes the parameter value to not be the plugin's config.

Checklist

• The Pull Request has tests
• A changelog file has been created under changelog/unreleased/kong or skip-changelog label added on PR if changelog is unnecessary. README.md
• There is a user-facing docs PR against https://github.com/Kong/docs.konghq.com - PUT DOCS PR HERE

Issue reference

KAG-4008
Fix #12442

[ADD-SP]

Please refine the changelog as customers might unable to understand it.

[ADD-SP]

One more question: there are two backport labels, did we decided to backport this fix?

[chronolaw]

Do we have test case to verify this issue is fixed?

[Water-Melon]

Do we have test case to verify this issue is fixed?

This issue was reproduced using my personal domain name + EC2 instance and was verified after the fix.

[ADD-SP]

In general, we should add tests for bugfix before merging.

[Water-Melon]

The test for this ticket requires binding a public IP address to a domain name, and then configuring it according to the instructions in https://docs.konghq.com/hub/kong-inc/acme/how-to/ . Afterward, send a PATCH request (also in this document), and we will see this error log in Kong's logs:

... attempt to index local 'config' (a boolean value), context: ngx.timer

After fixing it, if we execute it again, there will be no error log output, and the API will still return {"message":"Renewal process started successfully"}.

[chronolaw]

It seems that it is hard to write a test case for this PR, so I approve it.

[ADD-SP]

Missing tests, converted to a draft.

[team-gateway-bot]

Successfully created backport PR for release/3.5.x:

• [backport -> release/3.5.x] fix(plugins/acme): fix certificate renew failure issue #12801

[team-gateway-bot]

Successfully created backport PR for release/3.6.x:

• [backport -> release/3.6.x] fix(plugins/acme): fix certificate renew failure issue #12802

[team-gateway-bot]

Successfully created cherry-pick PR for master:

• https://github.com/kong/kong-ee/pull/8659