Feature summary (what you would like to be able to do and where):
There should be a custom license field for the new "own work" option in UploadWizard, as it already exists for the "not own work" option.

Use case(s) (list the steps that you performed to discover that problem, and describe the actual underlying problem which you want to solve. Do not describe only a solution):
All the cases in which the uploader do not want to stick with CC BY-SA, CC BY or CC0 as a license for their media.

Benefits (why should this be implemented?):
Because Commons guidelines allow for other free licenses to be used, if the uploader wants.