[css-align] Remove bad link

Author: tabatkins

css-align/Overview.bs

@@ -1063,7 +1063,7 @@ Inline/Main-Axis Alignment: the 'justify-self' property</h3>
 			<th><a>Alignment Subject</a>
 			<td>
 				The box's margin box,
-				assuming the <a>writing mode</a> of the <a>box</a>.
+				assuming the <a>writing mode</a> of the box.
 		<tr>
 			<th>''justify-self/normal'' Behavior
 			<td>