face: remove pointless method UdpFace::handleFirstReceive

Simply call DatagramFace::receiveDatagram directly.

Change-Id: Icec976fb9f4a008d08ece56c28ac652ea615bc76
diff --git a/daemon/face/datagram-face.hpp b/daemon/face/datagram-face.hpp
index bae4fb2..6f111e7 100644
--- a/daemon/face/datagram-face.hpp
+++ b/daemon/face/datagram-face.hpp
@@ -64,12 +64,9 @@
   close();
 
   void
-  handleSend(const boost::system::error_code& error,
-             const Block& wire);
-
-  void
-  handleReceive(const boost::system::error_code& error,
-                size_t nBytesReceived);
+  receiveDatagram(const uint8_t* buffer,
+                  size_t nBytesReceived,
+                  const boost::system::error_code& error);
 
   /**
    * \brief Set m_hasBeenUsedRecently to false
@@ -85,9 +82,12 @@
 
 protected:
   void
-  receiveDatagram(const uint8_t* buffer,
-                  size_t nBytesReceived,
-                  const boost::system::error_code& error);
+  handleSend(const boost::system::error_code& error,
+             const Block& wire);
+
+  void
+  handleReceive(const boost::system::error_code& error,
+                size_t nBytesReceived);
 
   void
   keepFaceAliveUntilAllHandlersExecuted(const shared_ptr<Face>& face);