rabbitmq: Fix repo for ubuntu aarch64

That has been omitted in the original patch.

Change-Id: I9b69fff14507ad2d1838367bb8b81a3a73694071
(cherry picked from commit 5bf0882)

Author: mnasiadka

kolla/template/repos.yaml

@@ -214,7 +214,7 @@ ubuntu:
 
 ubuntu-aarch64:
   erlang:
-    url: "https://launchpad.net/~rabbitmq/+archive/ubuntu/rabbitmq-erlang-25"
+    url: "https://ppa.launchpadcontent.net/rabbitmq/rabbitmq-erlang-25/ubuntu"
     suite: "jammy"
     component: "main"
     gpg_key: "erlang-ppa.gpg"