Complain more informatively about incorrect ENet versions

This was SVN commit r7897.

source/network/NetHost.cpp

@@ -19,11 +19,10 @@
 
 #include "NetHost.h"
 
+#include "lib/external_libraries/enet.h"
 #include "network/NetMessage.h"
 #include "ps/CLogger.h"
 
-#include <enet/enet.h>
-
 bool CNetHost::SendMessage(const CNetMessage* message, ENetPeer* peer, const char* peerName)
 {
 	ENetPacket* packet = CreatePacket(message);
@@ -77,4 +76,4 @@ void CNetHost::Initialize()
 void CNetHost::Deinitialize()
 {
 	enet_deinitialize();
-}
+}