Comment out SO_ERROR so it is not used

src/header/sys_socket/constants.rs

@@ -14,7 +14,7 @@ pub const SOL_SOCKET: c_int = 1;
 pub const SO_DEBUG: c_int = 1;
 pub const SO_REUSEADDR: c_int = 2;
 pub const SO_TYPE: c_int = 3;
-pub const SO_ERROR: c_int = 4;
+//pub const SO_ERROR: c_int = 4;
 pub const SO_DONTROUTE: c_int = 5;
 pub const SO_BROADCAST: c_int = 6;
 pub const SO_SNDBUF: c_int = 7;