Add missing bottom border for user dashboards

Change-Id: I8e025051199db539e00c4a329dc8d1a0942d4861
diff --git a/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.html b/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.html
index c8f606b..e129cee 100644
--- a/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.html
+++ b/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.html
@@ -38,6 +38,9 @@
       .hide {
         display: none;
       }
+      gr-user-header {
+        border-bottom: 1px solid #ddd;
+      }
       @media only screen and (max-width: 50em) {
         .loading {
           padding: 0 var(--default-horizontal-margin);