Running with JDK 11 generates warning

[dturanski]

9-Aug-2020 14:56:33	WARNING: An illegal reflective access operation has occurred
19-Aug-2020 14:56:33	WARNING: Illegal reflective access by com.esotericsoftware.kryo.util.UnsafeUtil (jar:file:/opt/bamboo-home/xml-data/build-dir/SCDT-LSM2SM2-RDFATFKJ1/local/skipper-server/skipper-server.jar!/BOOT-INF/lib/kryo-shaded-4.0.2.jar!/) to constructor java.nio.DirectByteBuffer(long,int,java.lang.Object)
19-Aug-2020 14:56:33	WARNING: Please consider reporting this to the maintainers of com.esotericsoftware.kryo.util.UnsafeUtil
19-Aug-2020 14:56:33	WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
19-Aug-2020 14:56:33	WARNING: All illegal access operations will be denied in a future release

The kryo dependency comes from spring-statemachine-data-jpa and used here:

https://github.com/spring-cloud/spring-cloud-skipper/blob/master/spring-cloud-skipper-server-core/src/main/java/org/springframework/cloud/skipper/server/statemachine/StateMachinePersistConfiguration.java#

See also https://github.com/EsotericSoftware/kryo/issues/747