[TIMOB-2117] Move itens to a blank Header in TableView on Edit crash App.

When you move an item to an empty category in Tableview crashes the application.

See sample code above:

var win = Ti.UI.createWindow();

var Data = [
    {header:'A',title:"test 1"},
    {title:"test 2"},
    {header:'B',title:"test 3"},
    {header:'C',title:"test 4"},
    {title:"test 5"}
];

var Table = Ti.UI.createTableView({
    style: Ti.UI.iPhone.TableViewStyle.PLAIN,
    editable:true,
    moveable:true,
    data:Data
});

Table.editing = true;

win.add(Table);
win.open();

Now run this code, Drag the "test 3" to outsite of "B" and then drag ANY item to inside "B". The App will CRASH.