Fix TypeError caused by empty lists being passed as a string to re.sub.
In make_api_response, empty lists were not JSONized because they were mistakenly detected as a None, which caused these empty lists to be passed to urlize_links_and_mails, which expects strings.
It caused a TypeError when calling re.sub() on it, which was catched so it still returned a result (and a correct one, since empty lists don't need substitution).
This commit removes the catch workaround and always passes the right type.
Resolves Sentry issue SWH-WEBAPP-H1
Test Plan
already covered by tests.
Migrated from D4819 (view on Phabricator)