*: make GNU licensing statement forms more regular

This change retains "or later" state! No licensing _changes_ here,
only form is adjusted (article, space between "GPL" and "v2" and so on).

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/networking/httpd_ssi.c b/networking/httpd_ssi.c
index 03f2633..87f43fc 100644
--- a/networking/httpd_ssi.c
+++ b/networking/httpd_ssi.c
@@ -1,7 +1,7 @@
 /*
  * Copyright (c) 2009 Denys Vlasenko <vda.linux@googlemail.com>
  *
- * Licensed under GPLv2, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2, see file LICENSE in this source tree.
  */
 
 /*