Issue 120: sentinel reporting error writing to config file. open(O_RDONLY)...

Issue 120: sentinel reporting error writing to config file. open(O_RDONLY) followed by fsync() would result in access denied error in windows. In the context of the code changed, ifdefing out fsync on Windows was the safest thing to do.

src/sentinel.c

@@ -1714,7 +1714,9 @@ void sentinelFlushConfig(void) {
 
     if (rewrite_status == -1) goto werr;
     if ((fd = open(server.configfile,O_RDONLY,0)) == -1) goto werr;
+#ifndef _WIN32
     if (fsync(fd) == -1) goto werr;
+#endif
     if (close(fd) == EOF) goto werr;
     return;