Maintenance: Stabilize user profile popover selenium test case.

spec/system/user/profile_spec.rb

@@ -35,7 +35,7 @@ RSpec.describe 'User Profile', type: :system do
   end
 
   it 'check that ignored attributes for user popover are not visible' do
-    fill_in id: 'global-search', with: customer.firstname
+    fill_in id: 'global-search', with: customer.email
 
     popover_on_hover(find('.nav-tab--search.user'))