Resolves Issue #13689

Doing this the right way this time. Hiding .panel-footer top border when
preceeded by a .list-group. This should resolve the "double border"
issue.

dist/css/bootstrap.css

@@ -4993,6 +4993,9 @@ a.list-group-item-danger.active:focus {
 .panel-heading + .list-group .list-group-item:first-child {
   border-top-width: 0;
 }
+.list-group + .panel-footer {
+  border-top-width: 0;
+}
 .panel > .table,
 .panel > .table-responsive > .table {
   margin-bottom: 0;

less/panels.less

@@ -86,7 +86,9 @@
     border-top-width: 0;
   }
 }
-
+.list-group + .panel-footer {
+  border-top-width: 0;
+}
 
 // Tables in panels
 //