FIxed bug when accessing length

Author: pontusmelke

src/v1/internal/features.js

@@ -27,7 +27,7 @@ const FEATURES = {
       // that supports reading the whole certificate, eg this commit:
       // https://github.com/nodejs/node/commit/345c40b6
       let desc = require('tls').TLSSocket.prototype.getPeerCertificate;
-      return desc.length() >= 1;
+      return desc.length >= 1;
     } catch( e ) {
       return false;
     }