JNI-135 - Fixed. use finalize() to release JNI-allocated mem. (Autocloseable never called close())

src/codegen/gen_java_Message.ysl2

@@ -68,6 +68,11 @@ tstylesheet {
                     release(handle);
                 }
 
+                @Override
+                public void finalize() {
+                    release(handle);
+                }
+
                 final protected long getHandle() {
                     return handle;
                 }