changing the ross message size parameter in dragonfly config file

tests/modelnet-test-dragonfly.conf

@@ -20,6 +20,6 @@ PARAMS
    local_bandwidth="5.25";
    global_bandwidth="4.7";
    cn_bandwidth="5.25";
-   message_size="2048";
+   message_size="512";
    routing="minimal";
 }