Don't define INVALID_SOCKET if it has been defined already (i.e. by libpcap) (#1021)

TobaYn3 · thomas-behn · web-flow · commit a58f0426148d · 2021-08-10T08:29:27.000-04:00
Co-authored-by: Thomas Behn &lt;Thomas.Behn@meinberg.de&gt;
diff --git a/httplib.h b/httplib.h
@@ -178,7 +178,9 @@ using socket_t = SOCKET;
 #include <unistd.h>
 
 using socket_t = int;
+#ifndef INVALID_SOCKET
 #define INVALID_SOCKET (-1)
+#endif
 #endif //_WIN32
 
 #include <algorithm>
