decouple use_syslog from pid_flags

Sometimes we need processes to run in the foreground to be supervised
and at the same time use syslog facility instead of logging its stdout,
stderr output

src/server.c

@@ -1726,8 +1726,8 @@ main(int argc, char **argv)
     }
 #endif
 
+    USE_SYSLOG(argv[0], pid_flags);
     if (pid_flags) {
-        USE_SYSLOG(argv[0]);
         daemonize(pid_path);
     }