'Upload' button is disabled inappropriately.

[jdkim]

Sometimes, the 'upload' button is disabled inappropriately.

To reproduce the problem,
(1) make a change to the annotation,
(2) click the 'upload' button,
(3) see the JSON source code, and
(4) get back to the editor.
You will see the 'upload' button is disabled.

[jdkim]

fixed