fix copyright message

Author: dexterlb

contrib/change_group_leader.lua

@@ -1,7 +1,7 @@
 --[[
   Passport cropping guide for darktable
 
-  copyright (c) 2021 Angel Angelov
+  copyright (c) 2022 Bill Ferguson <[email protected]>
 
   darktable is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -17,10 +17,6 @@
   along with darktable.  If not, see <http://www.gnu.org/licenses/>.
 ]]
 
---[[
-  Original author: github.com/wpferguson
-]]
-
 --[[
 CHANGE GROUP LEADER
 automatically change the leader of raw+jpg paired image groups