Support older getaddrinfo() missing AI_NUMERICSERV

Define this flag as 0 if unavailable.
This is needed for my OS X 10.5 system.

Signed-off-by: John Hood <cgull@glup.org>

src/network/network.cc

@@ -55,6 +55,10 @@
 #define MSG_DONTWAIT MSG_NONBLOCK
 #endif
 
+#ifndef AI_NUMERICSERV
+#define AI_NUMERICSERV 0
+#endif
+
 using namespace std;
 using namespace Network;
 using namespace Crypto;