zsh: update copyright notices

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/completion/git-completion.zsh

@@ -2,7 +2,7 @@
 
 # zsh completion wrapper for git
 #
-# Copyright (c) 2012-2013 Felipe Contreras <felipe.contreras@gmail.com>
+# Copyright (c) 2012-2020 Felipe Contreras <felipe.contreras@gmail.com>
 #
 # The recommended way to install this script is to make a copy of it as a
 # file named '_git' inside any directory in your fpath.

t/t9902-completion.sh

@@ -1,6 +1,6 @@
 #!/bin/sh
 #
-# Copyright (c) 2012 Felipe Contreras
+# Copyright (c) 2012-2020 Felipe Contreras
 #
 
 test_description='test bash completion'