Fix incorrect setting of opt_local_file in mysqlimport, for named pipe

For named pipe, server and client are on the same machine, and
opt_local_infile just adds unnecessary copying via "load data local infile"

client/mysqlimport.c

@@ -249,7 +249,6 @@ get_one_option(const struct my_option *opt, const char *argument,
 #ifdef __WIN__
   case 'W':
     opt_protocol = MYSQL_PROTOCOL_PIPE;
-    opt_local_file=1;
     break;
 #endif
   case OPT_MYSQL_PROTOCOL: