Censor URIs in service profile log

Summary: Mailgun requests can hit a credentialed URI. Censor credentials from `--trace` URIs.

Test Plan: Ran `bin/mail send-test ... --trace` and saw censored credentials.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Differential Revision: https://secure.phabricator.com/D8833