Fix styling issue with Layout Builder UX on the alert message of ( You are editing the layout .. ) over the first Add section

Captured by the Automated functional testing

https://travis-ci.com/github/Vardot/varbase/jobs/342061430#L1968

Before the fix

https://www.drupal.org/sites/all/modules/bueditor/icons/x1.png

After the fix

Feature: Landing (Layout Builder) Pages - Check to add sections and choose layouts for sections
As a logged in user with a permission to mange Landing (Layout Builder) pages
I want to be able to add sections with any layouts to the page
So that the "Landing (Layout Builder) page" will show up having the listed section with their content

  @javascript @local @development @staging @production
  Scenario: Check if a user with a permission to manage Landing page (Layout Builder) content type can add sections with any layouts to the page
    Given I am a logged in user with the "test_site_admin" user
     When I go to "node/add/landing_page_lb"
      And I wait
     Then I should see "Create Landing page (Layout Builder)"
     When I fill in "Full Width - No Background Color - Text only" for "Title"
      And I fill in "Test Landing page (Layout Builder) description" for "Page description"
      And I press "Save"
      And I wait
     Then I should see "Landing page (Layout Builder) Full Width - No Background Color - Text only has been created"
      And I should see "Layout"
     When I click "Layout"
      And I wait
     Then I should see "Edit layout for Full Width - No Background Color - Text only"
     When I click "Add section"
      And I wait for AJAX to finish
     Then I should see "Choose a layout for this section"
      And I should see "One column"
      And I should see "Two column"
      And I should see "Three column"
      And I should see "Four column"