Dropbox API v2 fails with "Unknown Content-type"

When combining OAuth2 and QOAuthOobReplyHandler the Dropbox API's /oauth2/token endpoint fails.

Apparently, it seems that "Content-type" included in this endpoint reply is returned by "text/javascript" instead of "application/json".

The specification about "Content-type" of this endpoint is not written in API document.

It seems that it always fails in networkReplyFinished() in qoauthoobreplyhandler.cpp because text/javascript" is not permitted.

Reference link:

• Dropbox API v2 document
  https://www.dropbox.com/developers/documentation/http/documentation
• NetworkStorageAccessSample
  https://github.com/sharkpp/NetworkStorageAccessSample
  In this source, it is designed to work by applying a monkey patch.
  dropbox.cpp, 'fix content-type, "text/javascript" to "application/json"' comments
  Needs:
  DEFINES+=DROPBOX_APP_KEY=" {dropbox app key}

  " DEFINES+=DROPBOX_APP_SECRET="

  {dropbox app secret}

  "
  in QMake addtional options.