Fix e2e create merge request test

Add QA selector to 'New label' button on empty labels page

app/views/shared/empty_states/_labels.html.haml

@@ -8,7 +8,7 @@
       %p= _("You can also star a label to make it a priority label.")
       .text-center
         - if can?(current_user, :admin_label, @project)
-          = link_to _('New label'), new_project_label_path(@project), class: 'btn btn-success', title: _('New label'), id: 'new_label_link'
+          = link_to _('New label'), new_project_label_path(@project), class: 'btn btn-success qa-label-create-new', title: _('New label'), id: 'new_label_link'
           = link_to _('Generate a default set of labels'), generate_project_labels_path(@project), method: :post, class: 'btn btn-success btn-inverted', title: _('Generate a default set of labels'), id: 'generate_labels_link'
         - if can?(current_user, :admin_label, @group)
           = link_to _('New label'), new_group_label_path(@group), class: 'btn btn-success', title: _('New label'), id: 'new_label_link'