currently I merged #8382 however there is still followup work to do.
the maintainer of jjwt is actually not really responsive.

See:

• Using Base64 instead of DatatypeConverter jwtk/jjwt#318
• closes #282: Fix Java9 jaxb problem jwtk/jjwt#283

Currently we should actually either do the following:

• try to contact the author of the library to raise jjwt to work only on java 8 and upwards and merge 318
• fork jjwt and pull Using Base64 instead of DatatypeConverter jwtk/jjwt#318 and rerelease it under the play banner (this comes with the fact that we need to do maintenance over the project)
• change to com.auth0 % java-jwt % 3.3.0 (maybe this library uses java.util.Base64 already or another library)

we can also keep the situation as is, the other pr jwtk/jjwt#283 would actually do the same thing than we did and just pull jaxb-api, depending if jjwt will support older versions than java8 it might be the only solution for them.