fix #2864: add owner option to sync

instead of hard-coding 'backup@pam'. this allows a bit more flexibility
(e.g., syncing to a datastore that can directly be used as restore
source) without overly complicating things.

Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>

www/window/SyncJobEdit.js

@@ -62,6 +62,26 @@ Ext.define('PBS.window.SyncJobEdit', {
 	],
 
 	column2: [
+	    {
+		fieldLabel: gettext('Owner'),
+		xtype: 'pbsUserSelector',
+		name: 'owner',
+		allowBlank: true,
+		emptyText: 'backup@pam',
+		getSubmitData: function() {
+		    let me = this;
+		    let name = me.getName();
+		    let val = me.getSubmitValue();
+
+		    let data = {};
+		    if (val === null || val === "") {
+			data.delete = name;
+		    } else {
+			data[name] = val;
+		    }
+		    return data;
+		},
+	    },
 	    {
 		fieldLabel: gettext('Remove vanished'),
 		xtype: 'proxmoxcheckbox',