[DNS Recovery]: Revert the cleanup timeout code.

The UDP socket timeout is being relied on in production. Removing it
    is an unexceptable breaking change. Removing it increases the
    number of file descriptors used in production.

We will have to live with this code forever instead of enforcing
    a statsd client must be strictly closed policy.

cc @sh1mmer @kriskowal
We should log this as trace (or maybe info) so we know roughly how much cleanup we are doing.