do not use bundle terminology

apparently, bundle is also like a cert chain

src/docker.js

@@ -204,18 +204,18 @@ async function getAddonMounts(app) {
             break;
         }
         case 'tls': {
-            const bundle = await reverseProxy.getCertificatePath(app.fqdn, app.domain);
+            const certificatePath = await reverseProxy.getCertificatePath(app.fqdn, app.domain);
 
             mounts.push({
                 Target: '/etc/certs/tls_cert.pem',
-                Source: bundle.certFilePath,
+                Source: certificatePath.certFilePath,
                 Type: 'bind',
                 ReadOnly: true
             });
 
             mounts.push({
                 Target: '/etc/certs/tls_key.pem',
-                Source: bundle.keyFilePath,
+                Source: certificatePath.keyFilePath,
                 Type: 'bind',
                 ReadOnly: true
             });