Remove reference to the enterprise learn more article.

Not used anymore.

BUG=chromium:469980
TEST=manual

Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: Ia5837d0b26dfac93e6de456be2625877da24eb69
Reviewed-on: https://chromium-review.googlesource.com/951222Reviewed-by: Denis Kuznetsov <antrim@chromium.org>
Reviewed-by: Alexander Alekseev <alemate@chromium.org>
Commit-Queue: Roman Sorokin <rsorokin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#541873}

chrome/browser/resources/chromeos/login/oobe_screen_oauth_enrollment.js

@@ -24,8 +24,6 @@ login.createScreen('OAuthEnrollmentScreen', 'oauth-enrollment', function() {
   /** @const */ var STEP_ACTIVE_DIRECTORY_JOIN_ERROR =
       'active-directory-join-error';
 
-  /** @const */ var HELP_TOPIC_ENROLLMENT = 4631259;
-
   return {
     EXTERNAL_API: [
       'showStep',