Set danger variant to delete artifact button

Changelog: changed

app/views/projects/artifacts/_artifact.html.haml

@@ -57,5 +57,5 @@
             = sprite_icon('folder-open', css_class: 'gl-icon')
 
         - if can?(current_user, :destroy_artifacts, @project)
-          = link_to project_artifact_path(@project, artifact), data: { placement: 'top', container: 'body', confirm: _('Are you sure you want to delete these artifacts?') }, method: :delete, title: _('Delete artifacts'), ref: 'tooltip', aria: { label: _('Delete artifacts') }, class: 'gl-button btn btn-danger btn-icon has-tooltip' do
+          = link_to project_artifact_path(@project, artifact), data: { placement: 'top', container: 'body', confirm: _('Are you sure you want to delete these artifacts?'), confirm_btn_variant: "danger" }, method: :delete, title: _('Delete artifacts'), ref: 'tooltip', aria: { label: _('Delete artifacts') }, class: 'gl-button btn btn-danger btn-icon has-tooltip' do
             = sprite_icon('remove', css_class: 'gl-icon')