fixing a minor problem in loggp config file

tests/conf/modelnet-p2p-bw-loggp.conf

@@ -10,7 +10,7 @@ LPGROUPS
 PARAMS
 {
    packet_size="2147483648";
-   message_size="176";
+   message_size="208";
    modelnet="loggp";
    # scheduler options
    modelnet_scheduler="fcfs";