Upgrade to Jackson 2.7.4

Author: jhoeller

build.gradle

@@ -53,7 +53,7 @@ configure(allprojects) { project ->
 	ext.htmlunitVersion      = "2.20"
 	ext.httpasyncVersion     = "4.1.1"
 	ext.httpclientVersion    = "4.5.2"
-	ext.jackson2Version      = "2.7.3"
+	ext.jackson2Version      = "2.7.4"
 	ext.jasperreportsVersion = "6.2.1"
 	ext.javamailVersion      = "1.5.5"
 	ext.jettyVersion         = "9.3.8.v20160314"