Now waiting up to 5 seconds for uploader registration record.
Exception handling for incompatible MyTardis version.
We just monitor the first attempt to use MyTardis API functionality
which is currently only available in the "mydata" branch, and if
it fails, show an error dialog.
If the remote "wc -c" command fails with "No such file or directory",
we should return zero bytes uploaded, rather than raising an exception.