fixed background-color for disabled links in pagination ('none' isn't a valid...

fixed background-color for disabled links in pagination ('none' isn't a valid value for background-color property http://www.w3.org/TR/CSS2/colors.html#propdef-background-color)

lib/patterns.less

@@ -483,7 +483,7 @@ footer {
       }
       &.disabled a,
       &.disabled a:hover {
-        background-color: none;
+        background-color: transparent;
         color: @grayLight;
       }
       &.next a {