Using nodeblock with Panels causes fatal error on the panels_content interface of pages

Problem/Motivation

I recently upgraded to the latest version of nodeblock and when I tried to edit a panel I had a PHP Fatal error.
The Cause was that the block content returned by the hook_block_view in the nodeblock module is not a string but a Drupal renderable array. Through the module ctools and his function ctools_block_content_type_admin_info(), this "array content" is passed to the function filter_xss_admin() wich is waiting for a string parameter. This generate the fatal error.

Proposed resolution

Just before the return of the nodeblock function nodeblock_block_view(), I propose to generate the block render string in the property used by the ctools function named before to call the filter_xss_admin() function.