Normalize URLs before warning about mismatched URL

[szokeasaurusrex]

If the token-embedded and user-provided URLs only differ by a trailing slash, we should not warn about a mismatched URL.

Let's normalize the URLs before comparing.

Update: discussed with the team. The behavior will likely stay the same in the Sentry Wizard for now due to backwards-compatibility concerns, but we can improve the logic for comparing the URLs in the Sentry CLI. In the meantime, you can safely ignore this warning.

Originally posted by @szokeasaurusrex in #2137