fix confidential border issue as well as confidential styles leaking on new MR

app/assets/stylesheets/pages/note_form.scss

@@ -108,6 +108,7 @@
   background-color: $orange-50;
   border-radius: $border-radius-default $border-radius-default 0 0;
   border: 1px solid $border-gray-normal;
+  border-bottom: none;
   padding: 3px 12px;
   margin: auto;
   align-items: center;
@@ -132,22 +133,9 @@
   }
 }
 
-.not-confidential {
-  padding: 0;
-  border-top: none;
-}
-
-.right-sidebar-expanded {
-  .md-area {
-    border-radius: 0;
-    border-top: none;
-  }
-}
-
-.right-sidebar-collapsed {
-  .confidential-issue-warning {
-    border-bottom: none;
-  }
+.confidential-issue-warning + .md-area {
+  border-top-left-radius: 0;
+  border-top-right-radius: 0;
 }
 
 .discussion-form {

app/views/projects/_md_preview.html.haml

 - referenced_users = local_assigns.fetch(:referenced_users, nil)
 
 - if defined?(@issue) && @issue.confidential?
-  %li.confidential-issue-warning
+  .confidential-issue-warning
     = confidential_icon(@issue)
     %span This is a confidential issue. Your comment will not be visible to the public.
-- else
-  %li.confidential-issue-warning.not-confidential
 
 .md-area
   .md-header

spec/features/issues_spec.rb

@@ -729,7 +729,6 @@ describe 'Issues' do
       visit project_issue_path(project, issue)
 
       expect(page).not_to have_css('.is-confidential')
-      expect(page).to have_css('.is-not-confidential')
     end
   end
 end