Merge branch 'new-file-mobile-dropdown-fix' into 'master'

Fixed add to tree button on mobile

## What does this MR do?

Fixes an issue with the width of the add to tree button on mobile.

This was caused by acde2e30 adding `100%` width for mobile.

## Screenshots (if relevant)

![Screen_Shot_2016-09-14_at_10.52.41](/uploads/029877794411ef68f31091869b7b9618/Screen_Shot_2016-09-14_at_10.52.41.png)

## What are the relevant issue numbers?

Closes #22128

See merge request !6339

app/assets/stylesheets/pages/projects.scss

@@ -334,6 +334,10 @@ a.deploy-project-label {
   a {
     color: $gl-dark-link-color;
   }
+
+  .dropdown-menu {
+    width: 240px;
+  }
 }
 
 .last-push-widget {