vzdump: apt: notification: do not include domain in 'hostname' field

- The man page warns about the usage of `hostname -f`, since a host
   may have multiple domains (or none at all)
 - The fallback PVE::INotify::nodename() already only returned the
   hostname without the domain part
 - Fencing notifications didn't include the domain part anyway

This may result in soft-breakage for any users who have already relied
on the domain being present. If there is need for it, it could include
a fqdn metadata field.

The hostname property used for rendering the notification template
is unaffected for now.

Signed-off-by: Lukas Wagner <l.wagner@proxmox.com>

PVE/API2/APT.pm

@@ -348,7 +348,8 @@ __PACKAGE__->register_method({
 		# matchers.
 		my $metadata_fields = {
 		    type => 'package-updates',
-		    hostname => $hostname,
+		    # Hostname (without domain part)
+		    hostname => PVE::INotify::nodename(),
 		};
 
 		PVE::Notify::info(

PVE/VZDump.pm

@@ -516,10 +516,9 @@ sub send_notification {
 	    "See Task History for details!\n";
     };
 
-    my $hostname = get_hostname();
-
     my $notification_props = {
-	"hostname" => $hostname,
+	# Hostname, might include domain part
+	"hostname" => get_hostname(),
 	"error-message" => $err,
 	"guest-table" => build_guest_table($tasklist),
 	"logs" => $text_log_part,
@@ -533,7 +532,8 @@ sub send_notification {
 	# backup job id here... (I think pvescheduler would need
 	# to pass that to the vzdump call?)
 	type => "vzdump",
-	hostname => $hostname,
+	# Hostname (without domain part)
+	hostname => PVE::INotify::nodename(),
     };
 
     my $severity = $failed ? "error" : "info";