debian/copyright: Minor fixes

- Update copyright year for fonts based on information embedded in .ttf file.

- Remove incorrect copyright text.

- Each session should have only one copyright line.

- Fix syntax for multiple licenses.

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>

debian/copyright

@@ -10,8 +10,7 @@ License: AGPL-3+
 Files: static/themes/default/FreedomBox-Logo.7z
 Copyright: 2012 Robert Martinez
 Comment: http://thread.gmane.org/gmane.linux.debian.freedombox.user/4124/focus=4439
-License: GPL-3+-or-CC-BY-SA
-  Some rights reserved.
+License: GPL-3+ or CC-BY-SA
 
 Files: static/themes/default/icons/deluge.png
 Copyright: 2007 Andrew Wedderburn
@@ -106,12 +105,10 @@ Files: static/themes/default/img/FreedomBox-logo-*
 Copyright: 2012 Robert Martinez
 Comment: http://thread.gmane.org/gmane.linux.debian.freedombox.user/4124/focus=4439
 License: GPL-3+ or CC-BY-SA
-  Some rights reserved.
 
 Files: static/themes/default/img/network-*
 Copyright: 2005-2009 Tango Desktop Project
 License: public-domain
- The Tango base icon theme is released to the Public Domain.
 
 Files: static/themes/default/img/network-computer.svg
 Copyright: 2008 GNOME icon artists
@@ -122,10 +119,9 @@ Files: static/themes/default/img/network-freedombox.svg
 Copyright: 2012 Robert Martinez
 Comment: http://thread.gmane.org/gmane.linux.debian.freedombox.user/4124/focus=4439
 License: GPL-3+ or CC-BY-SA
-  Some rights reserved.
 
 Files: static/themes/default/lato/*
-Copyright: (c) 2010-2011, Łukasz Dziedzic
+Copyright: (c) 2010-2014, Łukasz Dziedzic
 License: OFL-1.1
 
 Files: plinth/tests/coverage/coverage.py
@@ -134,7 +130,7 @@ License: GPL-3+
 
 Files: debian/*
 Copyright: 2013 Tzafrir Cohen
-Copyright: 2013-2019 FreedomBox Authors
+           2013-2019 FreedomBox Authors
 License: GPL-2+
 
 License: BSD-3-clause