style links on system notes to look clickable

app/assets/javascripts/notes.js

@@ -926,6 +926,7 @@ require('vendor/task_list');
       const $element = $(e.target);
       const $closestSystemCommitList = $element.siblings('.system-note-commit-list');
 
+      $element.find('.fa').toggleClass('fa-angle-down').toggleClass('fa-angle-up');
       $closestSystemCommitList.toggleClass('hide-shade');
     };
 

app/assets/stylesheets/pages/notes.scss

@@ -72,6 +72,7 @@ ul.notes {
       overflow: hidden;
 
       .system-note-commit-list-toggler {
+        color: $gl-link-color;
         display: none;
         padding: 10px 0 0;
         cursor: pointer;
@@ -107,16 +108,6 @@ ul.notes {
             display: none;
           }
 
-          p:last-child {
-            a {
-              color: $gl-text-color;
-
-              &:hover {
-                color: $gl-link-color;
-              }
-            }
-          }
-
           &::after {
             content: '';
             width: 100%;

app/views/projects/notes/_note.html.haml

@@ -77,6 +77,7 @@
         - if note.system
           .system-note-commit-list-toggler
             Toggle commit list
+            %i.fa.fa-angle-down
       - if note.attachment.url
         .note-attachment
           - if note.attachment.image?