Fix wiki errors in development nodes

Go to https://dev.labdoo.org/content/about-labdoo you will see the error: 'Notice: Trying to get property of non-object in node_page_title() (line 2202 of /var/www/lbd/modules/node/node.module).'

It appears that somewhere we are passing the node UD to node_page_title() instead of an actual node.

Adding this code:

function node_page_title($node) {
if(!property_exists($node, 'title'))
labdoo_lib_print_array($node);
return $node->title;
}

Will print this message:

70

Which is the node ID of about-labdoo page.