Error rendering logo

Hello,

Thanks for making this invoice plugin for wordpress.
I have for the second time a problem with your plugin.

Warning: file_get_contents(): php_network_getaddresses: getaddrinfo failed: Name or service not known in
/home/pensioenwiki/public_html/pensioenwiki/wp-content/plugins/woocommerce-pdf-invoices/functions.php
on line 13
Warning: file_get_contents(http://www.pensioenwiki.nl/wp-content/uploads/2015/10/logo.jpg): failed to open stream:
php_network_getaddresses: getaddrinfo failed: Name or service not known in
/home/pensioenwiki/public_html/pensioenwiki/wp-content/plugins/woocommerce-pdf-invoices/functions.php
on line 13

Yes i have allow_url_fopen open. The image works but what is the problem?

https://wordpress.org/plugins/woocommerce-pdf-invoices/