Fix XML formatting when generating an override

Go to:
http://explorer.nuxeo.com/nuxeo/site/distribution/Nuxeo%20DM-8.2/viewContribution/org.nuxeo.ecm.platform.comment.defaultPermissions--permissions
Click on generate override
Activate a checkbox (no matter which one)
Click on Generate XML file

=>

XML Parsing Error: not well-formed
Location: http://explorer.nuxeo.com/nuxeo/site/distribution/Nuxeo%20DM-8.2/viewContribution/org.nuxeo.ecm.platform.comment.defaultPermissions--permissions/override
Line Number 65, Column 13: <!-- The Version permission is deprecated
------------^