Increase animation speed of sticky issue header

Changelog: changed

Increase animation speed of sticky issue header
0245bd6a · Annabel Dunstone Gray · 5ccc773c · 0245bd6a
--- a/app/assets/stylesheets/pages/issues.scss
+++ b/app/assets/stylesheets/pages/issues.scss
@@ -318,7 +318,7 @@ ul.related-merge-requests > li gl-emoji {
 .issuable-header-slide-enter-active,
 .issuable-header-slide-leave-active {
-  @include gl-transition-slow;
+  @include gl-transition-medium;
 }
 .issuable-header-slide-enter,