Re-read credmon's pid file periodically.  #5974
Re-read credmon's pid file periodically.  #5974

If the credmon exits and restarts, this ensures its clients quickly
notice and start talking to the new process.

htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor