Bug#895837: jruby: Please package 9.1.16.0 or more recent releases

[Emmanuel Bourg]

It seems upgrading to 9.1.16 isn't enough [1], we need at least JRuby
9.2.1 for a good compatibility with Java 9, 10 and 11.

https://github.com/jruby/jruby/issues/5446#issuecomment-438732326