fix #4234: vzdump: add cluster-wide configuration

Introduce a cluster-wide vzdump.conf file which gets filled with the
default vzdump configuration.

Signed-off-by: Leo Nunner <l.nunner@proxmox.com>

data/PVE/Cluster.pm

@@ -45,6 +45,7 @@ my $dbbackupdir = "/var/lib/pve-cluster/backup";
 # using a computed version and only those can be used by the cfs_*_file methods
 my $observed = {
     'vzdump.cron' => 1,
+    'vzdump.conf' => 1,
     'jobs.cfg' => 1,
     'storage.cfg' => 1,
     'datacenter.cfg' => 1,

data/src/status.c

@@ -89,6 +89,7 @@ static memdb_change_t memdb_change_array[] = {
 	{ .path = "priv/ipam.db" },
 	{ .path = "datacenter.cfg" },
 	{ .path = "vzdump.cron" },
+	{ .path = "vzdump.conf" },
 	{ .path = "jobs.cfg" },
 	{ .path = "ha/crm_commands" },
 	{ .path = "ha/manager_status" },