NotifTroubleshootingScreen: Make email-sent log line actually reach S…

…entry

An alternative approach to zulip#5720, to help us detect potential cases
where the user thought they'd contacted support through the app, but
we don't see an email on our side. (We're not aware of such cases
yet, but in principle it could happen.)

It seems probably fine to do it at the "warn" level rather than
"info". If someone sends one of these emails, it usually means
something's not quite right with notifications somewhere, making
"warn" probably at least as appropriate as "info" in more cases than
not.

src/settings/NotifTroubleshootingScreen.js

@@ -408,7 +408,7 @@ export default function NotifTroubleshootingScreen(props: Props): React.Node {
         break;
       case MailComposer.MailComposerStatus.SENT:
         showToast(_('Email sent'));
-        logging.info('NotifTroubleshootingScreen: MailComposer reports a sent email.');
+        logging.warn('NotifTroubleshootingScreen: MailComposer reports a sent email.');
         break;
       case MailComposer.MailComposerStatus.UNDETERMINED:
         logging.warn('MailComposerStatus.UNDETERMINED');