Copyright for rng-tools-debian source package in Focal

This package was assembled by Henrique de Moraes Holschuh ,
based on previous work by Viral Shah .

Upstream sources are at: http://sourceforge.net/projects/gkernel/
  (module rng-tools)

The Debian packaging of rng-tools-debian is:
  Copyright © 2014, 2019 mirabilos ,
	    © 2015 by mirabilos ,
  Copyright (c) 2003-2010 by Henrique de Moraes Holschuh ,
  Copyright (c) 2002 by Viral Shah ,
  and distributed under the same license as the upstream source it applies to.

Changes:
  The Debian version of rngd is extensively patched with added
  functionality and bugs courtesy of Henrique de Moraes Holschuh.
  All changes were supposed to be proposed to be merged upstream, but the
  deviation got too large to handle, so it hasn't happened.  See upstream
  changelog for a list of all changes.

Upstream Authors:
  Philipp Rumpf,
  Jeff Garzik 
  Henrique de Moraes Holschuh 

Copyright:
   Copyright (C) 2001 Philipp Rumpf
   Copyright (C) 2001 Jeff Garzik 
   Copyright (C) 2004-2010 Henrique de Moraes Holschuh 
   Copyright (C) 2019 mirabilos 

   This program is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published by the
   Free Software Foundation; either version 2, or (at your option) any
   later version.

The GPL may be found in /usr/share/common-licenses/GPL-2 on a Debian system.