Fix #12353: Scope table border reset in panels to first-child rows

dist/css/bootstrap.css

@@ -4837,8 +4837,8 @@ a.list-group-item-danger.active:focus {
 .panel > .panel-body + .table-responsive {
   border-top: 1px solid #ddd;
 }
-.panel > .table > tbody:first-child th,
-.panel > .table > tbody:first-child td {
+.panel > .table > tbody:first-child > tr:first-child th,
+.panel > .table > tbody:first-child > tr:first-child td {
   border-top: 0;
 }
 .panel > .table-bordered,

less/panels.less

@@ -107,8 +107,8 @@
   > .panel-body + .table-responsive {
     border-top: 1px solid @table-border-color;
   }
-  > .table > tbody:first-child th,
-  > .table > tbody:first-child td {
+  > .table > tbody:first-child > tr:first-child th,
+  > .table > tbody:first-child > tr:first-child td {
     border-top: 0;
   }
   > .table-bordered,