Merge pull request #11494 from blowsie/patch-2

Fixed single dropdown-toggle in btn-group-veritcal not being rounded

less/button-groups.less

@@ -187,13 +187,13 @@
 .btn-group-vertical > .btn-group:not(:first-child):not(:last-child) > .btn {
   border-radius: 0;
 }
-.btn-group-vertical > .btn-group:first-child {
+.btn-group-vertical > .btn-group:first-child:not(:last-child) {
   > .btn:last-child,
   > .dropdown-toggle {
     .border-bottom-radius(0);
   }
 }
-.btn-group-vertical > .btn-group:last-child > .btn:first-child {
+.btn-group-vertical > .btn-group:last-child:not(:first-child) > .btn:first-child {
   .border-top-radius(0);
 }