cert: do not autoclean default cert

src/reverseproxy.js

@@ -695,7 +695,7 @@ async function cleanupCerts(auditSource, progressCallback) {
         locations = locations.concat(appLocationsSync(app));
     }
 
-    const certsInUse = [];
+    const certsInUse = [ 'default.cert' ];
     for (const location of locations) {
         const certificatePath = await getCertificatePath(location.fqdn, location.domain);
         certsInUse.push(path.basename(certificatePath.certFilePath));