do string compare in certs

src/directoryserver.js

@@ -368,7 +368,7 @@ async function stop() {
 
 async function handleCertChanged() {
     const certificate = await reverseProxy.getDirectoryServerCertificate();
-    if (certificate.cert.equals(gCertificate.cert)) {
+    if (certificate.cert === gCertificate.cert) {
         debug('handleCertChanged: certificate has not changed');
         return;
     }