docs: admin-guide: update kdump documentation due to change of crash URL

Since crash utility has been moved to github, the original URL is no
longer available. Let's update it accordingly.
Suggested-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Link: https://lore.kernel.org/r/a088bff5-1174-25fa-ac26-6e46795f4085@redhat.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/admin-guide/kdump/kdump.rst

@@ -509,9 +509,12 @@ ELF32-format headers using the --elf32-core-headers kernel option on the
 dump kernel.
 
 You can also use the Crash utility to analyze dump files in Kdump
-format. Crash is available on Dave Anderson's site at the following URL:
+format. Crash is available at the following URL:
 
-   http://people.redhat.com/~anderson/
+   https://github.com/crash-utility/crash
+
+Crash document can be found at:
+   https://crash-utility.github.io/
 
 Trigger Kdump on WARN()
 =======================