Wrong module auto-registered when using JPMS

[karbi]

As I understand module com.fasterxml.jackson.datatype.jsr310.JSR310Module is left for compatibility and com.fasterxml.jackson.datatype.jsr310.JavaTimeModule should be default one. However when using ObjectMapper.findAndRegisterModules() with JPMS in Java9+ JSR310Module is loaded as declared in module-info.java.

It should be changed as in #126 to maintain same behavior between modularized and non-modularized environments.

[cowtowncoder]

Yes, you are absolutely correct @karbi. Happy to merge this, but as per my comment on PR, needs to be against 2.15 -- although I think it's the right thing to do I am hesitant to do this in patch as it's technically changing behavior.

[cowtowncoder]

Merged in 2.15 branch to be included in 2.15.0.