build: Always build in C++11 mode.

Change-Id: Id8c26bc5951a0b60c4f2f0868ad0167b2f0d56af
Refs: #2103
diff --git a/src/state.cpp b/src/state.cpp
index 9d434ec..251d46b 100644
--- a/src/state.cpp
+++ b/src/state.cpp
@@ -57,7 +57,7 @@
 
     SeqNo old = (*leaf)->getSeq();
     m_leaves.modify(leaf,
-                    bind(&Leaf::setSeq, _1, seq));
+                    [=] (LeafPtr& leaf) { leaf->setSeq(seq); } );
     return make_tuple(false, true, old);
   }
 }