Added missing file extension to upload function
Added missing file extension to upload function

dtaalbers/ionic-example-app,dtaalbers/ionic-2-examples,dtaalbers/FileTransferExample,dtaalbers/FileTransferExample,dtaalbers/ionic-example-app,dtaalbers/ionic-2-examples,dtaalbers/FileTransferExample,dtaalbers/ionic-example-app,dtaalbers/ionic-example-app,dtaalbers/ionic-2-examples