release_2976

All PRs included

PR #2173 Add missing / to URL in overseas passports
PR #2030 Add link to Hong Kong passport in Cantonese
PR #2170 Upgrade airbrake gem to version 4.1.0
PR #2171 Updates production log stash configuration option
PR #2167 Remove i18n code

PRs to check post-deploy

PR #2030 Add link to Hong Kong passport in Cantonese