Drop alternative Suggests on btrfs-tools

Closes: #932122

Security support for Xen in Debian 8 -- for which this was still
needed -- has long ended.

debian/changelog

@@ -1,3 +1,10 @@
+xen-tools (4.9.2-2) UNRELEASED; urgency=medium
+
+  * Drop alternative Suggests on btrfs-tools. (Closes: #932122; Security
+    support for Xen in Debian 8 has long ended.)
+
+ -- Axel Beckert <abe@debian.org>  Mon, 11 Dec 2023 23:11:47 +0100
+
 xen-tools (4.9.2-1) unstable; urgency=medium
 
   * New upstream maintenance release

debian/control

@@ -51,7 +51,7 @@ Recommends: debian-archive-keyring,
             ubuntu-keyring | ubuntu-archive-keyring,
             xen-hypervisor,
             xen-utils
-Suggests: btrfs-progs | btrfs-tools,
+Suggests: btrfs-progs,
           cfengine2,
           grub-xen-host,
           reiserfsprogs,