Python: Catch and cope with unknown exceptions in the scanner
Python: Catch and cope with unknown exceptions in the scanner

This is to avoid the scanner getting stuck when the client gets an error
from the server or a certificate's parsing fails with an unknown exception.
While there is no recovery for LogClient errors, at least the scanner
will not get wedged and the error will be obvious in the output.

ksmaheshkumar/certificate-transparency,AlCutter/certificate-transparency,katjoyce/certificate-transparency,ksmaheshkumar/certificate-transparency,RJPercival/certificate-transparency,Martin2112/certificate-transparency,rep/certificate-transparency,grandamp/certificate-transparency,eranmes/certificate-transparency,grandamp/certificate-transparency,katjoyce/certificate-transparency,benlaurie/certificate-transparency,phad/certificate-transparency,eranmes/certificate-transparency,Martin2112/certificate-transparency,google/certificate-transparency,RJPercival/certificate-transparency,plietar/certificate-transparency,benlaurie/certificate-transparency,benlaurie/certificate-transparency,katjoyce/certificate-transparency,kyprizel/certificate-transparency,lexibrent/certificate-transparency,AlCutter/certificate-transparency,RJPercival/certificate-transparency,taknira/certificate-transparency,kyprizel/certificate-transparency,ksmaheshkumar/certificate-transparency,AlCutter/certificate-transparency,lexibrent/certificate-transparency,phad/certificate-transparency,Martin2112/certificate-transparency,rep/certificate-transparency,rep/certificate-transparency,Martin2112/certificate-transparency,katjoyce/certificate-transparency,eranmes/certificate-transparency,benlaurie/certificate-transparency,google/certificate-transparency,plietar/certificate-transparency,RJPercival/certificate-transparency,aeijdenberg/certificate-transparency,grandamp/certificate-transparency,katjoyce/certificate-transparency,aeijdenberg/certificate-transparency,plietar/certificate-transparency,katjoyce/certificate-transparency,ksmaheshkumar/certificate-transparency,pphaneuf/certificate-transparency,kyprizel/certificate-transparency,rep/certificate-transparency,eranmes/certificate-transparency,taknira/certificate-transparency,taknira/certificate-transparency,kyprizel/certificate-transparency,benlaurie/certificate-transparency,pphaneuf/certificate-transparency,ksmaheshkumar/certificate-transparency,AlCutter/certificate-transparency,phad/certificate-transparency,google/certificate-transparency,aeijdenberg/certificate-transparency,rep/certificate-transparency,katjoyce/certificate-transparency,google/certificate-transparency,rep/certificate-transparency,aeijdenberg/certificate-transparency,taknira/certificate-transparency,benlaurie/certificate-transparency,Martin2112/certificate-transparency,kyprizel/certificate-transparency,pphaneuf/certificate-transparency,aeijdenberg/certificate-transparency,rep/certificate-transparency,Martin2112/certificate-transparency,AlCutter/certificate-transparency,Martin2112/certificate-transparency,grandamp/certificate-transparency,AlCutter/certificate-transparency,eranmes/certificate-transparency,kyprizel/certificate-transparency,phad/certificate-transparency,taknira/certificate-transparency,ksmaheshkumar/certificate-transparency,taknira/certificate-transparency,aeijdenberg/certificate-transparency,eranmes/certificate-transparency,taknira/certificate-transparency,plietar/certificate-transparency,benlaurie/certificate-transparency,lexibrent/certificate-transparency,eranmes/certificate-transparency,aeijdenberg/certificate-transparency,kyprizel/certificate-transparency,pphaneuf/certificate-transparency,plietar/certificate-transparency,AlCutter/certificate-transparency,plietar/certificate-transparency,lexibrent/certificate-transparency,plietar/certificate-transparency,ksmaheshkumar/certificate-transparency