Merge branch 'jivanvl-replace-alert-uploads' into 'master'

Replace alert for gl-alert in blob/upload

See merge request gitlab-org/gitlab!43350

app/views/projects/blob/_upload.html.haml

@@ -15,7 +15,7 @@
                 #{ dropzone_text.html_safe }
 
           %br
-          .dropzone-alerts.alert.alert-danger.data{ style: "display:none" }
+          .dropzone-alerts.gl-alert.gl-alert-danger.gl-mb-5.data{ style: "display:none" }
 
           = render 'shared/new_commit_form', placeholder: placeholder