Upgrade to Jackson 2.9.0.pr4

Issue: SPR-15548

Author: sdeleuze

build.gradle

@@ -58,7 +58,7 @@ configure(allprojects) { project ->
 	ext.httpasyncVersion       = "4.1.3"
 	ext.httpclientVersion      = "4.5.3"
 	ext.interceptorApiVersion  = "1.2"
-	ext.jackson2Version        = "2.9.0.pr3"
+	ext.jackson2Version        = "2.9.0.pr4"
 	ext.javamailVersion        = "1.6.0-rc2"
 	ext.jaxbVersion            = "2.2.11"
 	ext.jaxwsVersion           = "2.2.11"