StdRemoveButton: enable by default if no selection model

As in that case we normally want it to be enabled from the start, as
no selection model is there and so we cannot wait until one item is
selected until we enable it.

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

button/Button.js

@@ -155,5 +155,16 @@ Ext.define('Proxmox.button.StdRemoveButton', {
 		Ext.Msg.alert(gettext('Error'), response.htmlStatus);
 	    }
 	});
+    },
+    initComponent: function() {
+	let me = this;
+
+	// enable by default if no seleModel is there and disabled not set
+	if (me.initialConfig.disabled === undefined
+	    && (me.selModel === null || me.selModel === false)) {
+	    me.disabled = false;
 	}
+
+	me.callParent();
+    },
 });