Remove class which has no effect

app/views/projects/tracings/show.html.haml

@@ -3,7 +3,7 @@
 
 - if @project.tracing_external_url.present?
   %h3.page-title= _('Tracing')
-  .gl-alert.gl-alert-info.gl-mb-5.flex-alert
+  .gl-alert.gl-alert-info.gl-mb-5
     .gl-alert-container
       = sprite_icon('information-o', css_class: 'gl-icon gl-alert-icon gl-alert-icon-no-title')
       .gl-alert-content