build: Always build in C++11 mode.

Change-Id: Ib3adcb0f2faff2e8bd2036d4e296052c5eaef94f
diff --git a/src/controller-backend.cpp b/src/controller-backend.cpp
index af84cd7..7d9f4ef 100644
--- a/src/controller-backend.cpp
+++ b/src/controller-backend.cpp
@@ -143,7 +143,7 @@
 {
   // _LOG_DEBUG("onInvitationInterest: " << interest.getName());
   shared_ptr<Interest> invitationInterest =
-    make_shared<Interest>(boost::cref(interest.getName().getSubName(routingPrefixOffset)));
+    make_shared<Interest>(interest.getName().getSubName(routingPrefixOffset));
 
   // check if the chatroom already exists;
   try {