webui: set auto scrolling to true for general tv adapter panel

Without this you can't scroll down to the save button of this panel.

src/webui/static/app/dvb.js

@@ -1228,6 +1228,7 @@ tvheadend.dvb_adapter_general = function(adapterData, satConfStore) {
 	var panel = new Ext.Panel({
 		title : 'General',
 		layout : 'column',
+		autoScroll : true,
 		items : [ toolpanel, confform, infoPanel ]
 	});