JasPer 2.0.16 got recently released.

I would like to see a transition to OpenJPEG as suggested in #5849 but in the meantime I think updating the sources for libjasper might be a good idea since it fixes two CVEs.

I would have created a PR instead but looking at the to me unfamilar directory structure at opencv/3rdparty/libjasper I'll rather let you handle it properly.