JRobin: Fix for Java 9 to remove dependency on Sun private classes

https://github.com/OpenNMS/jrobin/issues/3
http://stackoverflow.com/questions/1854398/how-to-garbage-collect-a-direct-buffer-java
Code from http://sourceforge.net/p/tuer/code/HEAD/tree/pre_beta/src/main/java/engine/misc/DeallocationHelper.java
unmodified, GPLv2

router/java/src/net/i2p/router/RouterVersion.java

@@ -18,7 +18,7 @@ public class RouterVersion {
     /** deprecated */
     public final static String ID = "Monotone";
     public final static String VERSION = CoreVersion.VERSION;
-    public final static long BUILD = 4;
+    public final static long BUILD = 5;
 
     /** for example "-test" */
     public final static String EXTRA = "";