Use lowercase names for Windows headers Otherwise we can't cross-compile on Linux.
diff --git a/src/netops.c b/src/netops.c
index 4d461a0..e16cae8 100644
--- a/src/netops.c
+++ b/src/netops.c
@@ -12,9 +12,9 @@
# include <netdb.h>
#else
# include <winsock2.h>
-# include <Ws2tcpip.h>
+# include <ws2tcpip.h>
# ifdef _MSC_VER
-# pragma comment(lib, "Ws2_32.lib")
+# pragma comment(lib, "ws2_32.lib")
# endif
#endif