Fixes #12625: Only remove first list group item's top and last list group...

Fixes #12625: Only remove first list group item's top and last list group item's bottom borders when the list group is first or last

dist/css/bootstrap.css

@@ -4796,17 +4796,13 @@ a.list-group-item-danger.active:focus {
   border-width: 1px 0;
   border-radius: 0;
 }
-.panel > .list-group .list-group-item:first-child {
-  border-top: 0;
-}
-.panel > .list-group .list-group-item:last-child {
-  border-bottom: 0;
-}
 .panel > .list-group:first-child .list-group-item:first-child {
+  border-top: 0;
   border-top-left-radius: 3px;
   border-top-right-radius: 3px;
 }
 .panel > .list-group:last-child .list-group-item:last-child {
+  border-bottom: 0;
   border-bottom-right-radius: 3px;
   border-bottom-left-radius: 3px;
 }

less/panels.less

@@ -58,25 +58,23 @@
 .panel {
   > .list-group {
     margin-bottom: 0;
+
     .list-group-item {
       border-width: 1px 0;
       border-radius: 0;
-      &:first-child {
-        border-top: 0;
-      }
-      &:last-child {
-        border-bottom: 0;
-      }
     }
+
     // Add border top radius for first one
     &:first-child {
       .list-group-item:first-child {
+        border-top: 0;
         .border-top-radius((@panel-border-radius - 1));
       }
     }
     // Add border bottom radius for last one
     &:last-child {
       .list-group-item:last-child {
+        border-bottom: 0;
         .border-bottom-radius((@panel-border-radius - 1));
       }
     }