Debug Log: Undefined variable

Hi

in my debug log, I see the following line

[11-Aug-2016 07:08:07 UTC] PHP Notice: Undefined variable: CurUlr in /var/www/virtual/url.de/htdocs/wp-content/plugins/custom-amp-accelerated-mobile-pages/classes/class-amp-related-posts-embed.php on line 33

Any ideas?

https://wordpress.org/plugins/custom-amp-accelerated-mobile-pages/

[Moderator note: Please, no bumping.]