Make the project avatar preview a rectangle

app/views/projects/settings/_general.html.haml

@@ -32,7 +32,7 @@
   = render_if_exists 'shared/repository_size_limit_setting', form: f, type: :project
 
   .form-group.gl-mt-3.gl-mb-3
-    .avatar-container.s90
+    .avatar-container.rect-avatar.s90
       = project_icon(@project, alt: _('Project avatar'), class: 'avatar project-avatar s90')
     = f.label :avatar, _('Project avatar'), class: 'label-bold d-block'
     = render 'shared/choose_avatar_button', f: f