Bug: "No data found to update." when reverting a Profile value

[bcholmes]

On the Participant Profile page, if the user makes a change, hits update, and then reverts that change and hits update again (without leaving the page), they'll get an error message ("No data found to update. Database not updated.").

Technical details: because the page submits changes using Ajax, the page is not refreshed after the update button is pressed. If you make a change to the page, press update, and then revert that change and press update, the form's "defaultValue" for the changed field is the same as the original value (even though the database no longer contains that value). The JavaScript for myProfile.js will skip sending the field to the server (because it matches the defaultValue) and the server won't make any changes.

While this seems like a rare set of circumstances, I think it can easily come up if the user makes a change and then changes their mind.