catalog-operator repeatedly crashes with "runtime error: index out of range [0] with length 0"

Issue

• After updating to OpenShift Container Platform 4.6.4, the catalog-operator in the namespace 'openshift-operator-lifecycle-manager' will stay in state 'CrashLoopBackOff'. The following error messages are shown:

  [..]
  time="2020-11-11T09:41:45Z" level=info msg=syncing event=update reconciling="*v1alpha1.Subscription" selflink=/apis/operators.coreos.com/v1alpha1/namespaces/openshift-operators/subscriptions/abc-def-operator
  time="2020-11-11T09:41:45Z" level=info msg=syncing id=VyvNB ip=install-7k27n namespace=customer-example phase=Complete
  time="2020-11-11T09:41:45Z" level=info msg=syncing event=update reconciling="*v1alpha1.Subscription" selflink=/apis/operators.coreos.com/v1alpha1/namespaces/example-argocd/subscriptions/argocd-operator
  time="2020-11-11T09:41:45Z" level=info msg=syncing id=0tbFL ip=install-nskss namespace=customer-example phase=Complete
  time="2020-11-11T09:41:45Z" level=info msg=syncing event=update reconciling="*v1alpha1.Subscription" selflink=/apis/operators.coreos.com/v1alpha1/namespaces/example-argocd/subscriptions/argocd-operator
  time="2020-11-11T09:41:45Z" level=info msg="state.Key.Namespace=openshift-marketplace state.Key.Name=certified-operators state.State=CONNECTING"
  panic: runtime error: index out of range [0] with length 0
  
  goroutine 632 [running]:
  github.com/operator-framework/operator-lifecycle-manager/pkg/controller/registry/reconciler.imageID(...)
  /build/pkg/controller/registry/reconciler/grpc.go:313
  github.com/operator-framework/operator-lifecycle-manager/pkg/controller/registry/reconciler.imageChanged(0xc002f34500, 0xc00a6eeeb8, 0x1, 0x1, 0x0)
  /build/pkg/controller/registry/reconciler/grpc.go:300 +0x32d
  github.com/operator-framework/operator-lifecycle-manager/pkg/controller/registry/reconciler.(*GrpcRegistryReconciler).ensureUpdatePod(0xc00aba8570, 0xc000237200, 0xc00a6eee00, 0x0)
  /build/pkg/controller/registry/reconciler/grpc.go:238 +0x3ca
  github.com/operator-framework/operator-lifecycle-manager/pkg/controller/registry/reconciler.(*GrpcRegistryReconciler).EnsureRegistryServer(0xc00aba8570, 0xc000237200, 0xc00b73b230, 0x1)
  /build/pkg/controller/registry/reconciler/grpc.go:158 +0xc7
  github.com/operator-framework/operator-lifecycle-manager/pkg/controller/operators/catalog.(*Operator).syncRegistryServer(0xc000639cc0, 0xc00b765880, 0xc00052db00, 0xc00052db00, 0xc0004edc01, 0x0, 0x0)
  /build/pkg/controller/operators/catalog/operator.go:625 +0x331
  github.com/operator-framework/operator-lifecycle-manager/pkg/controller/operators/catalog.(*Operator).syncCatalogSources.func1(0xc00052db00, 0xc00a1d8100, 0x4, 0x4, 0x1, 0x4800c5, 0x3)
  /build/pkg/controller/operators/catalog/operator.go:741 +0x79
  github.com/operator-framework/operator-lifecycle-manager/pkg/controller/operators/catalog.(*Operator).syncCatalogSources(0xc000639cc0, 0x1c96800, 0xc000363720, 0xc00b765730, 0x1d9fba8)
  /build/pkg/controller/operators/catalog/operator.go:788 +0x409
  github.com/operator-framework/operator-lifecycle-manager/pkg/lib/queueinformer.LegacySyncHandler.ToSyncerWithDelete.func1(0x1f4eb00, 0xc0007be740, 0x1f1dd40, 0xc00a1d80c0, 0xc00a1d80c0, 0x1b4aa00)
  /build/pkg/lib/queueinformer/queueinformer.go:183 +0x26e
  github.com/operator-framework/operator-lifecycle-manager/pkg/lib/kubestate.SyncFunc.Sync(0xc000466fa0, 0x1f4eb00, 0xc0007be740, 0x1f1dd40, 0xc00a1d80c0, 0xc00b765501, 0x0)
  /build/pkg/lib/kubestate/kubestate.go:184 +0x4e
  github.com/operator-framework/operator-lifecycle-manager/pkg/lib/queueinformer.(*QueueInformer).Sync(...)
  /build/pkg/lib/queueinformer/queueinformer.go:36
  github.com/operator-framework/operator-lifecycle-manager/pkg/lib/queueinformer.(*operator).processNextWorkItem(0xc000151ef0, 0x1f4eb00, 0xc0007be740, 0xc000cad3e0, 0x0)
  /build/pkg/lib/queueinformer/queueinformer_operator.go:287 +0x348
  github.com/operator-framework/operator-lifecycle-manager/pkg/lib/queueinformer.(*operator).worker(0xc000151ef0, 0x1f4eb00, 0xc0007be740, 0xc000cad3e0)
  /build/pkg/lib/queueinformer/queueinformer_operator.go:231 +0x49
  created by github.com/operator-framework/operator-lifecycle-manager/pkg/lib/queueinformer.(*operator).start
  /build/pkg/lib/queueinformer/queueinformer_operator.go:221 +0x45d