bankruptcy: Fix narrow being lost on declaring bankruptcy.

This was actually being done in 2 ways: via not saving the narrow in
the reload and second through calling `change_tab_to('#home')`.  The
code is so ancient that it seems unlikely that this behavior was still
intentional.

Fixes part of #3687 (the remainder is fixed in a few commits).

static/js/pointer.js

@@ -64,10 +64,9 @@ exports.fast_forward_pointer = function () {
             unread_ops.mark_all_as_read(function () {
                 pointer.furthest_read = data.max_message_id;
                 unconditionally_send_pointer_update().then(function () {
-                    ui_util.change_tab_to('#home');
                     reload.initiate({immediate: true,
                                      save_pointer: false,
-                                     save_narrow: false,
+                                     save_narrow: true,
                                      save_compose: true});
                 });
             });