[gimp-help] Update copyright years

[Alexandre Prokoudine <aprokoudine src gnome org>]

commit 94dc3048f0841dc3aa9222df50f066f1aabf9e26
Author: Alexandre Prokoudine <alexandre prokoudine gmail com>
Date:   Fri Sep 7 09:55:17 2018 +0000

    Update copyright years

 web/layout.xml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/web/layout.xml b/web/layout.xml
index ddfb7c39d..e6a876b7e 100644
--- a/web/layout.xml
+++ b/web/layout.xml
@@ -4,7 +4,7 @@
 
 <layout>
   <copyright>
-    <year>2001-2013</year>
+    <year>2001—2018</year>
     <holder role="gimp-help">The GIMP Help Team (Graphics by Jakub Steiner)</holder>
   </copyright>
   <style src="style.css" type="text/css" />