Remove use of deprecated and now removed QueueBase::MaxPackets

Change-Id: I6aa6d2af4e6189ecd6bac774b2b846b18a0f9dd2
diff --git a/examples/ndn-simple-mpi.cpp b/examples/ndn-simple-mpi.cpp
index f15af34..6be5e5c 100644
--- a/examples/ndn-simple-mpi.cpp
+++ b/examples/ndn-simple-mpi.cpp
@@ -74,7 +74,7 @@
   // setting default parameters for PointToPoint links and channels
   Config::SetDefault("ns3::PointToPointNetDevice::DataRate", StringValue("1Gbps"));
   Config::SetDefault("ns3::PointToPointChannel::Delay", StringValue("1ms"));
-  Config::SetDefault("ns3::QueueBase::MaxPackets", UintegerValue(10));
+  Config::SetDefault("ns3::QueueBase::MaxSize", StringValue("10p"));
 
   bool nullmsg = false;