Upgrade to Jackson 2.9.9

Author: jhoeller

build.gradle

@@ -32,7 +32,7 @@ ext {
 	freemarkerVersion    = "2.3.28"
 	groovyVersion        = "2.5.7"
 	hsqldbVersion        = "2.4.1"
-	jackson2Version      = "2.9.8"
+	jackson2Version      = "2.9.9"
 	jettyVersion         = "9.4.18.v20190429"
 	junit5Version        = "5.3.2"
 	kotlinVersion        = "1.2.71"