Add border radius and overflow hidden to .postbox

Author: shreyasikhar

src/wp-admin/css/edit.css

@@ -191,6 +191,8 @@ body.post-type-wp_navigation .inline-edit-status {
 	position: relative;
 	min-width: 255px;
 	border: 1px solid #c3c4c7;
+	border-radius: 8px;
+	overflow: hidden;
 	box-shadow: 0 1px 1px rgba(0, 0, 0, 0.04);
 	background: #fff;
 }