[core] remove fdevent_sched_run from fdevent_libev (#2827)

remove fdevent_sched_run from fdevent_libev.c
(redundant since commit 8ed588ce)

x-ref:
  "POST to mod_cgi sometimes hangs"
  https://redmine.lighttpd.net/issues/2827

src/fdevent_libev.c

@@ -100,7 +100,6 @@ static int fdevent_libev_poll(fdevents *ev, int timeout_ms) {
 
 	ev_timer_again(ev->libev_loop, &timeout_watcher);
 	ev_run(ev->libev_loop, EVRUN_ONCE);
-	fdevent_sched_run(ev->srv, ev);
 
 	return 0;
 }