Update to Jackson 2.9.6

Fixes: gh-5424

gradle/dependency-management.gradle

@@ -40,9 +40,9 @@ dependencyManagement {
 		dependency 'asm:asm:3.1'
 		dependency 'ch.qos.logback:logback-classic:1.2.3'
 		dependency 'ch.qos.logback:logback-core:1.2.3'
-		dependency 'com.fasterxml.jackson.core:jackson-annotations:2.9.5'
-		dependency 'com.fasterxml.jackson.core:jackson-core:2.9.5'
-		dependency 'com.fasterxml.jackson.core:jackson-databind:2.9.5'
+		dependency 'com.fasterxml.jackson.core:jackson-annotations:2.9.6'
+		dependency 'com.fasterxml.jackson.core:jackson-core:2.9.6'
+		dependency 'com.fasterxml.jackson.core:jackson-databind:2.9.6'
 		dependency 'com.fasterxml:classmate:1.3.4'
 		dependency 'com.github.stephenc.jcip:jcip-annotations:1.0-1'
 		dependency 'com.google.appengine:appengine-api-1.0-sdk:1.9.64'