Fix for PHP Fatal error 

I am getting the following error 
```
 PHP Fatal error:  Access level to Redirection_Table::extra_tablenav() must be public (as in class WP_List_Table) in /var/www/inspirewp/web/wp-content/plugins/redirection/models/pager.php on line 204```

This is because this method was set to protected for some reason.
Merge pull request #13 from spacedmonkey/patch-1

Fix for PHP Fatal error