Fix dead link. Hopefully extract mysql details from environment

healthcheck

@@ -2,7 +2,10 @@
 
 export $(grep -v '^#' /etc/reminder-rs/config.env | xargs -d '\n')
 
-VAR=$(mysql -N -D reminders -e "SELECT COUNT(1) FROM reminders WHERE utc_time < NOW() - INTERVAL 10 MINUTE AND enabled = 1")
+REGEX='mysql://([A-Za-z]+)@(.+)/(.+)'
+[[ $DATABASE_URL =~ $REGEX ]]
+
+VAR=$(mysql -u "${BASH_REMATCH[1]}" -h "${BASH_REMATCH[2]}" -N -D "${BASH_REMATCH[3]}" -e "SELECT COUNT(1) FROM reminders WHERE utc_time < NOW() - INTERVAL 10 MINUTE AND enabled = 1")
 
 if [ "$VAR" -gt 0 ]
 then