Fix spelling

Author: ocaisa

_includes/expand-side-column

@@ -1,6 +1,6 @@
 {% comment %}
 * when the side column with the tags is displayed, we need to make it
-* as tall as the other side of the page, so the stickyness of the
+* as tall as the other side of the page, so the stickiness of the
 * 'back to the top' works. This jQuery is activated when scrolling happens
 * and checks that the screen is 628px wide to change the height of the column
 {% endcomment %}