Bump copyright notices for 2021. Happy New Year!
diff --git a/src/metrics.h b/src/metrics.h
index ccc92a8..cecf8c8 100644
--- a/src/metrics.h
+++ b/src/metrics.h
@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
    
    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