This bug was fixed in the package grub2-signed - 1.66.6
--------------- grub2-signed (1.66.6) xenial; urgency=medium
* Rebuild against grub2 2.02~beta2-36ubuntu3.6. (LP: #1229458, #1519836)
-- Mathieu Trudel-Lapierre <email address hidden> Mon, 19 Dec 2016 21:12:45 -0500
This bug was fixed in the package grub2-signed - 1.66.6
---------------
grub2-signed (1.66.6) xenial; urgency=medium
* Rebuild against grub2 2.02~beta2- 36ubuntu3. 6. (LP: #1229458, #1519836)
-- Mathieu Trudel-Lapierre <email address hidden> Mon, 19 Dec 2016 21:12:45 -0500