Description of problem:
When installing using http proxy the installation hangs in "Finalizing" state

Controller logs:

time="2020-10-21T05:32:41Z" level=info msg="Cluster version is available:false , message:Working towards 4.6.0-rc.4: 78% complete"
time="2020-10-21T05:33:11Z" level=info msg="Waiting for cluster version to be available"
time="2020-10-21T05:33:11Z" level=info msg="Cluster version is available:false , message:Working towards 4.6.0-rc.4: 78% complete"
time="2020-10-21T05:33:41Z" level=info msg="Waiting for cluster version to be available"
time="2020-10-21T05:33:41Z" level=info msg="Cluster version is available:false , message:Working towards 4.6.0-rc.4: 78% complete"
time="2020-10-21T05:34:11Z" level=info msg="Waiting for cluster version to be available"
time="2020-10-21T05:34:11Z" level=info msg="Cluster version is available:false , message:Working towards 4.6.0-rc.4: 78% complete"

Cluster Version Operator Logs:

E1021 04:56:22.013534       1 event.go:273] Unable to write event: 'can't create an event with namespace 'default' in namespace 'openshift-cluster-version'' (may retry after sleeping)
E1021 04:56:22.013635       1 event.go:218] Unable to write event '&v1.Event{TypeMeta:v1.TypeMeta{Kind:"", APIVersion:""}, ObjectMeta:v1.ObjectMeta{Name:".163fe8e75b843788", GenerateName:"", Namespace:"default", SelfLink:"", UID:"", ResourceVersion:"", Generation:0, CreationTimestamp:v1.Time{Time:time.Time{wall:0x0, ext:0, loc:(*time.Location)(nil)}}, DeletionTimestamp:(*v1.Time)(nil), DeletionGracePeriodSeconds:(*int64)(nil), Labels:map[string]string(nil), Annotations:map[string]string(nil), OwnerReferences:[]v1.OwnerReference(nil), Finalizers:[]string(nil), ClusterName:"", ManagedFields:[]v1.ManagedFieldsEntry(nil)}, InvolvedObject:v1.ObjectReference{Kind:"ConfigMap", Namespace:"", Name:"", UID:"", APIVersion:"v1", ResourceVersion:"", FieldPath:""}, Reason:"LeaderElection", Message:"master-0-0_a2380518-ae40-4761-afaa-96c685400da2 stopped leading", Source:v1.EventSource{Component:"openshift-cluster-version", Host:""}, FirstTimestamp:v1.Time{Time:time.Time{wall:0xbfdc0da22bf7e788, ext:128205563418, loc:(*time.Location)(0x26b0400)}}, LastTimestamp:v1.Time{Time:time.Time{wall:0xbfdc0da22bf7e788, ext:128205563418, loc:(*time.Location)(0x26b0400)}}, Count:1, Type:"Normal", EventTime:v1.MicroTime{Time:time.Time{wall:0x0, ext:0, loc:(*time.Location)(nil)}}, Series:(*v1.EventSeries)(nil), Action:"", Related:(*v1.ObjectReference)(nil), ReportingController:"", ReportingInstance:""}' (retry limit exceeded!)
I1021 04:56:32.738209       1 start.go:260] Waiting on 1 outstanding goroutines.
E1021 04:56:32.738259       1 metrics.go:160] Failed to gracefully shut down metrics server: accept tcp [::]:9099: use of closed network connection
I1021 04:56:48.238826       1 discovery.go:214] Invalidating discovery information


Version-Release number of selected component (if applicable):
{
    "release_tag": "v1.0.10.1",
    "versions": {
        "assisted-ignition-generator": "",
        "assisted-installer": "registry-proxy.engineering.redhat.com/rh-osbs/openshift4-assisted-installer-rhel8:v4.6.0-28",
        "assisted-installer-controller": "registry-proxy.engineering.redhat.com/rh-osbs/openshift4-assisted-installer-reporter-rhel8:v4.6.0-25",
        "assisted-installer-service": "quay.io/app-sre/assisted-service:fd4fdf8",
        "discovery-agent": "quay.io/ocpmetal/assisted-installer-agent:latest",
        "image-builder": "quay.io/app-sre/assisted-iso-create:fd4fdf8"
    }
}

How reproducible:
Intermittently 

Steps to Reproduce:
1. Create cluster and generate ISO with http proxy set
2. Begin cluster installation

Actual results:
Cluster install hangs on "Finalizing"

Expected results:
Cluster install completed


Additional info: