fix building without --with-debug, introduced in r3294
diff --git a/src/os/unix/ngx_process_cycle.c b/src/os/unix/ngx_process_cycle.c
index 4b74030..e203ea3 100644
--- a/src/os/unix/ngx_process_cycle.c
+++ b/src/os/unix/ngx_process_cycle.c
@@ -170,7 +170,7 @@
 
         ngx_time_update(0, 0);
 
-        ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
+        ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
                        "wake up, sigio %i", sigio);
 
         if (ngx_reap) {