update copyright date

dev/paview/paview.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1983-2013 Trevor Wishart and Composers Desktop Project Ltd
+ * Copyright (c) 1983-2023 Trevor Wishart and Composers Desktop Project Ltd
  * http://www.trevorwishart.co.uk
  * http://www.composersdesktop.com
  *