Upgrade to Jackson 2.9.9

Author: jhoeller

build.gradle

@@ -40,7 +40,7 @@ ext {
 	freemarkerVersion    = "2.3.28"
 	groovyVersion        = "2.4.17"
 	hsqldbVersion        = "2.4.1"
-	jackson2Version      = "2.9.8"
+	jackson2Version      = "2.9.9"
 	jettyVersion         = "9.4.18.v20190429"
 	junitJupiterVersion  = "5.0.3"
 	junitPlatformVersion = "1.0.3"