comma for the guardian angel /cc @cvrebert

docs/assets/css/bootstrap.css

@@ -1486,7 +1486,8 @@ input[type="checkbox"]:focus {
   outline-offset: -2px;
 }
 
-input[type="number"]::-webkit-outer-spin-button input[type="number"]::-webkit-inner-spin-button {
+input[type="number"]::-webkit-outer-spin-button,
+input[type="number"]::-webkit-inner-spin-button {
   height: auto;
 }
 

less/forms.less

@@ -153,7 +153,7 @@ input[type="checkbox"]:focus {
 // Setting certain font-sizes causes the `I` bar to appear on hover of the bottom increment button.
 // See https://github.com/twitter/bootstrap/issues/8350 for more.
 input[type="number"] {
-  &::-webkit-outer-spin-button
+  &::-webkit-outer-spin-button,
   &::-webkit-inner-spin-button  {
     height: auto;
   }