misc: update copyright date

Change-Id: I1579fd8e6d77eb67b322ef22dedf0a1c8e6f1734
diff --git a/ringbutton.cpp b/ringbutton.cpp
index 6de7a40..ad743e1 100644
--- a/ringbutton.cpp
+++ b/ringbutton.cpp
@@ -1,5 +1,5 @@
 /***************************************************************************
- * Copyright (C) 2017 by Savoir-faire Linux                                *
+ * Copyright (C) 2017-2019 by Savoir-faire Linux                                *
  * Author: Jäger Nicolas <nicolas.jager@savoirfairelinux.com>              *
  *                                                                         *
  * This program is free software; you can redistribute it and/or modify    *