Correct colspan

Closes woocommerce#16698

Author: mikejolley

templates/order/order-details-item.php

@@ -52,7 +52,7 @@
 
 <tr class="woocommerce-table__product-purchase-note product-purchase-note">
 
-	<td colspan="3"><?php echo wpautop( do_shortcode( wp_kses_post( $purchase_note ) ) ); ?></td>
+	<td colspan="2"><?php echo wpautop( do_shortcode( wp_kses_post( $purchase_note ) ) ); ?></td>
 
 </tr>