Catch PDNSException in Signingpiper::helperWorker to avoid abort
Merge pull request #1685 from cmouse/catch-pdnsexception-signingpipe

Catch PDNSException in Signingpiper::helperWorker to avoid abort
fix possible fd leak in signpipe worker
Merge pull request #1687 from mind04/exception

fix possible fd leak in signpipe worker