Update the contrib/ejbca to 7.x, once available.
EJBCA 6.x doesn`t support IPv6 addresses used in certificate enrollment requests.

Such a support is planned for the 7.x release of ejbca, planned to be GA in 2021.
This story targets an update of reference ejbca version used in contrib.

EJBCA 7.x is already available (E03/21): https://sourceforge.net/projects/ejbca/files/ejbca7/
We wait for a Docker image to be released, and then we can start the work on this Story.