misc: update copyright date to 2021

Change-Id: I6cd0f36b983e38d9ed03362358dc145f3a12a49b

README.md

@@ -223,7 +223,7 @@ Compile the client with `BUILD=Debug` and compile LibRingClient with
 
 # License
 
-Copyright (C) 2020 Savoir-faire Linux Inc.
+Copyright (C) 2020-2021 Savoir-faire Linux Inc.
 
 Jami 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 3 of the License, or (at your option) any later version.
 

jami-qt.appdata.xml

 <?xml version="1.0" encoding="UTF-8"?>
-<!-- Copyright 2015-2020 Savoir-faire Linux -->
+<!-- Copyright 2015-2021 Savoir-faire Linux -->
 <component type="desktop-application">
  <id>net.jami.Jami</id>
  <metadata_license>CC-BY-SA-3.0</metadata_license>

src/constant/JamiStrings.qml

@@ -33,7 +33,7 @@ Item {
 
     // AboutPopUp
     property string version: qsTr("Version") + (UpdateManager.isCurrentVersionBeta() ? " (BETA)" : "")
-    property string companyDeclarationYear: "© 2015-2020 Savoir-faire Linux Inc."
+    property string companyDeclarationYear: "© 2015-2021 Savoir-faire Linux Inc."
     property string slogan: "Together"
     property string declaration: qsTr("Jami is a free software for universal communication which respects the freedom and privacy of its users.")
     property string credits: qsTr("Credits")