Be more defensive in etcd polling, catch various HTTP-related exceptions.
Be more defensive in etcd polling, catch various HTTP-related exceptions.

neiljerram/felix,neiljerram/felix,TrimBiggs/calico,ocadotechnology/calico,ocadotechnology/calico,neiljerram/felix,anortef/calico,Metaswitch/calico,beddari/calico,anortef/calico,matthewdupre/felix,kasisnu/calico,kasisnu/calico,matthewdupre/felix,alexhersh/calico,Metaswitch/calico,beddari/calico,alexhersh/calico,neiljerram/felix,TrimBiggs/calico