Grid layout 3(1) is not available for selection in admin dropdown

[kudosonline]

In the admin, the list of available options does not include '31', which should enable a product layout with 3 columns in desktop, 2 in tablet and 1 in mobile.

The patch below is a super quick mechanism to make it available.

--- a/woocommerce-twitterbootstrap.php
+++ b/woocommerce-twitterbootstrap.php
@@ -203,7 +203,7 @@ function showform()

        $numberofcolumns = (get_option('number_of_columns'))?get_option('number_of_columns'):4;

-       foreach(array(1,2,3,4,6) as $number)
+       foreach(array(1,2,3,31,4,6) as $number)
        {
                ?><option value="<?php echo $number ?>" <?php echo ($numberofcolumns==$number)?' selected="selected"':''?>><?php echo $number ?></
        }