Returns empty string if row is null. Fixes #951
Returns empty string if row is null. Fixes #951

Before would return row if falsy. That behavior is okay for a value of `0` but not null or undefined. This seems to only be a problem in IE or Edge.
swimlane/angular2-data-table,achimha/ngx-datatable,swimlane/angular2-data-table,swimlane/angular2-data-table,swimlane/ngx-datatable,achimha/ngx-datatable,achimha/ngx-datatable,swimlane/ngx-datatable,swimlane/ngx-datatable