Backport commit 2fcf2dff0 from Emacs

Fix copyright years by hand
2fcf2dff00a55ece17f4342a934cb1d69ae1a743
Paul Eggert
Tue Jan 1 01:02:40 2019 +0000

lisp/ox-html.el

@@ -234,7 +234,7 @@ property on the headline itself.")
 @licstart  The following is the entire license notice for the
 JavaScript code in this tag.
 
-Copyright (C) 2012-2018 Free Software Foundation, Inc.
+Copyright (C) 2012-2019 Free Software Foundation, Inc.
 
 The JavaScript code in this tag is free software: you can
 redistribute it and/or modify it under the terms of the GNU
@@ -537,7 +537,7 @@ means to use the maximum value consistent with other options."
  * @licstart  The following is the entire license notice for the
  *  JavaScript code in %SCRIPT_PATH.
  *
- * Copyright (C) 2012-2018 Free Software Foundation, Inc.
+ * Copyright (C) 2012-2019 Free Software Foundation, Inc.
  *
  *
  * The JavaScript code in this tag is free software: you can
@@ -566,7 +566,7 @@ means to use the maximum value consistent with other options."
 @licstart  The following is the entire license notice for the
 JavaScript code in this tag.
 
-Copyright (C) 2012-2018 Free Software Foundation, Inc.
+Copyright (C) 2012-2019 Free Software Foundation, Inc.
 
 The JavaScript code in this tag is free software: you can
 redistribute it and/or modify it under the terms of the GNU