Crier gerrit reporter: don't fail when a commit is deleted
Crier gerrit reporter: don't fail when a commit is deleted

Gerrit comments are attached to commits, there could be cases where the commit triggering the prowjobs were missing, which resulted in SetReview always fail, and crier would retry indefinitely until the job was GC'ed

jessfraz/test-infra,cblecker/test-infra,BenTheElder/test-infra,monopole/test-infra,cjwagner/test-infra,monopole/test-infra,cblecker/test-infra,fejta/test-infra,dims/test-infra,cjwagner/test-infra,monopole/test-infra,michelle192837/test-infra,michelle192837/test-infra,BenTheElder/test-infra,michelle192837/test-infra,cjwagner/test-infra,BenTheElder/test-infra,monopole/test-infra,fejta/test-infra,dims/test-infra,kubernetes/test-infra,fejta/test-infra,cblecker/test-infra,cblecker/test-infra,cjwagner/test-infra,fejta/test-infra,michelle192837/test-infra,cblecker/test-infra,jessfraz/test-infra,cjwagner/test-infra,jessfraz/test-infra,monopole/test-infra,BenTheElder/test-infra,kubernetes/test-infra,michelle192837/test-infra,kubernetes/test-infra,dims/test-infra,kubernetes/test-infra,BenTheElder/test-infra,jessfraz/test-infra,kubernetes/test-infra,michelle192837/test-infra,cblecker/test-infra,fejta/test-infra,fejta/test-infra,jessfraz/test-infra,BenTheElder/test-infra,dims/test-infra,jessfraz/test-infra,cjwagner/test-infra,kubernetes/test-infra,dims/test-infra,monopole/test-infra,dims/test-infra