Mention user function is different to original markdown editor

[yschao77]

@user function is different from original markdown editor

• Markdown edit and save: @user looks like a tag with blue background
  • HTML is <a class="user active user-mention" href="/users/18">@AliceWA Wu</a>
  • Notify @user by mail about the tracker
• Visual edit and save: It becomes a user link.
  • HTML is <a class="user active" href="/users/18">AliceWA Wu</a>

When I save @user with markdown editor first. Then, edit and save again by Visual Editor. It transfer to wrong syntax mentioned above.

Picture Reference:

Environment:
  Redmine version                5.0.5.stable
  Ruby version                   2.7.5-p203 (2021-11-24) [x86_64-linux-gnu]
  Rails version                  6.1.7.2
  Environment                    production
  Database adapter               PostgreSQL
Redmine settings:
  Redmine theme                  Default               
Redmine plugins:
  redmine_dashboard              2.14.0
  redmine_issue_templates        1.1.2
  redmine_issues_tree            0.0.15
  redmine_maintenance_mode       3.0.1
  redmine_pivot_table            0.0.8
  redmine_wysiwyg_editor         0.32.0

[taqueci]

Note to self:
https://www.redmine.org/issues/13919