fix timeout of age_callout_queue

[scholarchen]

timeout->tv_sec = (secs > 3) ? 3 : secs; // aimwang: set max timeout pselect return max timeout is 3 seconds not secs when Rt==0

[zocker007]

I have found that issue too and fixed it like in this PR. On FreeBSD, this patch works like expected.

I think this is the same as in #59 . When the solution there works like expected, I think we should probably use it over this because of portability.

[pali]

I guess that instead of using undefined value timeout->tv_sec you can use (secs > 3) ? 3 : secs or call clock_gettime with CLOCK_MONOTONIC.