Healthcheck returns exit code 1 when passing all tests

Prerequisites

• I have searched for duplicate or closed issues
• I can recreate the issue with all plugins disabled

Describe the issue

I'm running a test environment using docker. Just noticed the exit codes are returning incorrect values.

Recreate this by running

php /var/www/html/bin/healthcheck.sh ; echo $?

This is my output on a vanilla container, nothing is configured.

DB: OK
IMAP: OK (localhost:143)
SMTP: NOT OK (Failed to connect to localhost:587)
0

Setting up smtp and imap, you get the following.

DB: OK
IMAP: OK (REDACTED)
SMTP: OK (REDACTED)
1

Note the exit codes are backwards, it should exit 0 when everything is ok and 1 when there are errors.