Fix typo in attribute

Author: josepharhar

source

@@ -53796,7 +53796,7 @@ interface <dfn interface>HTMLSelectElement</dfn> : <span>HTMLElement</span> {
    then return.</p></li>
 
    <li><p>If <var>event</var> is a <code>MouseEvent</code> and <var>event</var>'s <code
-   data-x="dom-MouseEvent-button">button</code> atribute is not 1, then return.</p></li>
+   data-x="dom-MouseEvent-button">button</code> attribute is not 1, then return.</p></li>
 
    <li><p>Set <var>option</var>'s <span data-x="concept-option-selectedness">selectedness</span> to
    true.</p></li>