Fix broken `learn more` link for Campfire integration

What does this MR do and why?

We are fixing the broken learn more link from the integration page.

Additionally, we are cleaning the rubocop styling issues.

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Before	After

How to set up and validate locally

1. Checkout the branch
2. Visit the Campfire integration page (Settings/Integrations/Campfire)
3. Click on the learn more link.
4. Validate that the page is loaded correctly.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.