Upgrade the Jackson version to 2.9.9 as used for Elytron subsystem testing to match the version in WildFly.

Update FasterXml Jackson to 2.9.9.3 (2.9.9).

Community tag: https://github.com/FasterXML/jackson-databind/tree/jackson-databind-2.9.9.3
Diff: https://github.com/FasterXML/jackson-databind/compare/jackson-databind-2.9.8...jackson-databind-2.9.9.3