gnu: build: file-system: Change url of LUKS specification.

* gnu/build/file-system.scm: Change url of LUKS specification.

Signed-off-by: Efraim Flashner <efraim@flashner.co.il>

gnu/build/file-systems.scm

@@ -139,7 +139,7 @@ (define (ext2-superblock-volume-name sblock)
 ;;;
 
 ;; The LUKS header format is described in "LUKS On-Disk Format Specification":
-;; <http://wiki.cryptsetup.googlecode.com/git/LUKS-standard/>.  We follow
+;; <https://gitlab.com/cryptsetup/cryptsetup/wikis/Specification>.  We follow
 ;; version 1.2.1 of this document.
 
 (define-syntax %luks-endianness