ui: group filter: add hint that filter are additive

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

www/form/GroupFilter.js

@@ -331,12 +331,30 @@ Ext.define('PBS.form.GroupFilter', {
 		name: '{name}',
 	    },
 	},
+	{
+	    xtype: 'container',
+	    layout: {
+		type: 'hbox',
+	    },
+	    items: [
 		{
 		    xtype: 'button',
 		    text: gettext('Add'),
 		    iconCls: 'fa fa-plus-circle',
 		    handler: 'addFilter',
 		},
+		{
+		    xtype: 'box',
+		    flex: 1,
+		},
+		{
+		    xtype: 'box',
+		    style: 'margin: 3px 0px;',
+		    html: `<span class="pmx-hint">${gettext('Note')}</span>: `
+			+ gettext('Filters are additive (OR-like)'),
+		},
+	    ],
+	},
     ],
 
     initComponent: function() {