vendor-prefix-align: khtml prefix added

`-khtml` is really needed on special project for old browsers (Yandex lite version).

Author: mishanga

lib/options/vendor-prefix-align.js

@@ -2,6 +2,7 @@ module.exports = (function() {
     // Vendor prefixes list:
     var PREFIXES = [
         'webkit',
+        'khtml',
         'moz',
         'ms',
         'o'