Fix TCP behavior test with ephemeral port (#68)

by reading the local address from the last connection and reusing it
in the next one, to avoid OS allocating a new port each time

client/clientmain.cpp

@@ -304,7 +304,7 @@ void TcpClientLoop(StunClientLogicConfig& config, ClientSocketConfig& socketconf
     int sock;
     CRefCountedBuffer spMsg(new CBuffer(1500));
     CRefCountedBuffer spMsgReader(new CBuffer(1500));
-    CSocketAddress addrDest, addrLocal;
+    CSocketAddress addrDest, addrLocal = socketconfig.addrLocal;
     HRESULT hrRet, hrResult;
     int ret;
     size_t bytes_sent, bytes_recv;
@@ -327,7 +327,7 @@ void TcpClientLoop(StunClientLogicConfig& config, ClientSocketConfig& socketconf
     {
     
         stunsocket.Close();
-        hr = stunsocket.TCPInit(socketconfig.addrLocal, RolePP, true);
+        hr = stunsocket.TCPInit(addrLocal, RolePP, true);
         if (FAILED(hr))
         {
             Logging::LogMsg(LL_ALWAYS, "Unable to create local socket for TCP connection (hr == %x)", hr);