Fix compile errors when building on windows

Errors were due to not including winsock2 early enough.

src/common.h

@@ -24,6 +24,7 @@
 
 # include <io.h>
 # include <direct.h>
+# include <winsock2.h>
 # include <windows.h>
 # include "win32/msvc-compat.h"
 # include "win32/mingw-compat.h"

src/netops.c

@@ -12,7 +12,6 @@
 #	include <netdb.h>
 #       include <arpa/inet.h>
 #else
-#	include <winsock2.h>
 #	include <ws2tcpip.h>
 #	ifdef _MSC_VER
 #		pragma comment(lib, "ws2_32.lib")