**breaking change**: Switch Face and related classes to v2::KeyChain

security::v2::KeyChain is now exposed as ndn::KeyChain, which should
ensure that dependent code can be mostly compiled.  However, expect code
that explicitly uses the old KeyChain interface to be broken.

Change-Id: I7330d0250d92f3f0f2570ab6d0214ab3dfdd18cc
Refs: #3098
diff --git a/src/mgmt/dispatcher.cpp b/src/mgmt/dispatcher.cpp
index 62f9114..3220864 100644
--- a/src/mgmt/dispatcher.cpp
+++ b/src/mgmt/dispatcher.cpp
@@ -42,7 +42,7 @@
   };
 }
 
-Dispatcher::Dispatcher(Face& face, security::v1::KeyChain& keyChain,
+Dispatcher::Dispatcher(Face& face, KeyChain& keyChain,
                        const security::SigningInfo& signingInfo,
                        size_t imsCapacity)
   : m_face(face)