Update to 6.6.0

• Unbreak on FreeBSD 12+ (this version bundles an updated version of jRuby which allows running the PuppetServer on hosts with 64 bits inodes);
• Override the jRuby bundled ffi.rb to workaround a NullPointerException when trying to open an inexistent file;
• Remove deprecated Java flags;

Release notes:
https://puppet.com/docs/puppetserver/latest/release_notes.html#puppet-server-660

With hat: puppet