Merge branch '15081-wrong-login-tab-ldap-frontend' into 'master'

Fixed Wrong Tab Selected When Loggin Fails And Multiple Login Tabs Exists

## What does this MR do?
Fixes issue: 15081 Wrong Tab Selected When Loggin Fails And Multiple Login Tabs Exists
This is done by saving into a cookie when the active tab changes and by always selecting that tab when the page is loaded.
## Are there points in the code the reviewer needs to double check?
No
## Why was this MR needed?
In order to fix the issue: 15081
## Screenshots (if relevant)

## Does this MR meet the acceptance criteria?

- [x] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if it does - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?


Closes #15081

See merge request !7314

1 files changed, 1 insertions, 0 deletions

diff --git a/app/assets/javascripts/dispatcher.js.es6 b/app/assets/javascripts/dispatcher.js.es6
index 3a7c5ff3681..413117c2226 100644
--- a/app/assets/javascripts/dispatcher.js.es6
+++ b/app/assets/javascripts/dispatcher.js.es6
@@ -24,6 +24,7 @@
       switch (page) {
         case 'sessions:new':
           new UsernameValidator();
+          new ActiveTabMemoizer();
           break;
         case 'projects:boards:show':
         case 'projects:boards:index':