[PATCH] Remove warning about org-clock-save.el lacking lexical-binding directive

[Bastien]

Recent versions of Emacs complain about org-clock-save.el:

  ⛔ Warning (lexical-binding): File
  /home/bzg/.emacs.d/org-clock-save.el lacks `lexical-binding'
  directive on its first line

The attached patch should fix this.  Is it okay to add it to bugfix?

Thanks,

-- 
 Bastien

diff --git a/lisp/org-clock.el b/lisp/org-clock.el
index 67feb6b35..806bc02de 100644
--- a/lisp/org-clock.el
+++ b/lisp/org-clock.el
@@ -3233,7 +3233,7 @@ The details of what will be saved are regulated by the variable
 		 org-clock-has-been-used
 		 (not (file-exists-p org-clock-persist-file))))
     (with-temp-file org-clock-persist-file
-      (insert (format ";; %s - %s at %s\n"
+      (insert (format ";; %s - %s at %s -*- lexical-binding: t; -*-\n"
 		      (file-name-nondirectory org-clock-persist-file)
 		      (system-name)
 		      (format-time-string (org-time-stamp-format t))))