Virtualmin 5.0.6 downgrade to 5.0.5

This topic is made because a problem with https://www.virtualmin.com/node/48208

To confirm the Virtualmin have a bug in 5.0.6 I need to downgrade the latest Virtualmin to 5.0.5 version from November 2016.

How can I do it? Is there any risk?

Please advise