Notice: Undefined variable: post in …/admin/admin-function.php on line 81

Love your plugin! When I upgraded to wordpress 4.5 I am getting Notice: Undefined variable: post in …/wp-content/plugins/testimonial-rotator/admin/admin-functions.php on line 81 in the image column in backend.
Here is the website
http://urbanescargot.co.nz/about-us-nico-fini-urban-escargot/testimonials/

https://ww.wp.xz.cn/plugins/testimonial-rotator/