Transceiver: Add missing include netinet/in.h

Previous commit started using IPPROTO_UDP without including required
include. Newer versions of libosmocore's osmocom/core/socket.h include
that header so the define is present, but older versions of libosmocore
(such as 0.12.0) don't, so let's include it explicitly (the correct
thing to do).

Fixes: b9d2515704ac83cacd88d0a73ecba30323df0b2d
Change-Id: I67ddf550f3a7fc6a650e1e1d9bde0bbb28785104
diff --git a/Transceiver52M/Transceiver.cpp b/Transceiver52M/Transceiver.cpp
index b12a498..4da1876 100644
--- a/Transceiver52M/Transceiver.cpp
+++ b/Transceiver52M/Transceiver.cpp
@@ -24,6 +24,7 @@
 */
 
 #include <stdio.h>
+#include <netinet/in.h>
 #include <iomanip>      // std::setprecision
 #include <fstream>
 #include "Transceiver.h"