ConnectionManager: use peer certificate from TLS in closeConnectionsWith

Change-Id: I55ea604cc2542fb0d38b465cfa6a090450fe9322
diff --git a/src/multiplexed_socket.cpp b/src/multiplexed_socket.cpp
index 154741b..9c1f952 100644
--- a/src/multiplexed_socket.cpp
+++ b/src/multiplexed_socket.cpp
@@ -770,6 +770,12 @@
     return pimpl_->endpoint->getRemoteAddress();
 }
 
+TlsSocketEndpoint*
+MultiplexedSocket::endpoint()
+{
+    return pimpl_->endpoint.get();
+}
+
 void
 MultiplexedSocket::eraseChannel(uint16_t channel)
 {