Merge branch 'fix/ide-file-scroll-issue' into 'master'

fix Web IDE file tree scroll issue

See merge request gitlab-org/gitlab-ce!18721

app/assets/stylesheets/pages/repo.scss

@@ -440,6 +440,7 @@
   padding-right: 3px;
 
   .projects-sidebar {
+    min-height: 0;
     display: flex;
     flex-direction: column;
     flex: 1;