Correct production server url

Gruntfile.js

@@ -145,7 +145,7 @@ module.exports = function(grunt) {
             if (srcpath.match('libtextsecure')) {
               return content.replace(
                 /textsecure-service-staging.whispersystems.org/g,
-                'textsecure-service.whispersystems.org').replace(
+                'textsecure-service-ca.whispersystems.org:4433').replace(
                 /whispersystems-textsecure-attachments-staging.s3.amazonaws.com/g,
                 'whispersystems-textsecure-attachments.s3.amazonaws.com');
             } else {