Remove 'All messages' sidebar link.

Nobody uses it, and it causes confusion. (How is it different from 'Home'?)

For now, leave in the ability to get to the narrow, although we may
ultimately want to do away with it as well.

(imported from commit 35b3f27e39c4de3391bc5571b32f7242a29f4cfa)

static/js/ui.js

@@ -1562,7 +1562,6 @@ $(function () {
     hashchange.initialize();
     invite.initialize();
     activity.initialize();
-    subs.update_all_messages_link();
     tutorial.initialize();
     onboarding.initialize();
 });