Update to Freemarker 2.3.31

Closes gh-605

Author: jzheaux

odm/build.gradle

@@ -6,7 +6,7 @@ dependencies {
     compile project(":spring-ldap-core"),
             project(":spring-ldap-core-tiger"),
             "org.springframework:spring-core:$springVersion",
-            "org.freemarker:freemarker:2.3.20",
+            "org.freemarker:freemarker:2.3.31",
             "commons-logging:commons-logging:$commonsLoggingVersion",
             "commons-cli:commons-cli:1.2"