Description of problem:
Customer sees error messages [0] when adding the --confirm flag to the command `oadm prune images --keep-tag-revisions=3 --keep-younger-than=60m`

The registry is secured so under recommendation from engineering previously we attempted to add the --certificate-authority flag as well as the --registry-url flag but to no avail [1]

[0] 
error: error communicating with registry: Get http://172.30.74.39:5000/healthz: malformed HTTP response "\x15\x03\x01\x00\x02\x02"

At the same time the registry logs print:
I0417 14:11:26.845937       1 logs.go:41] http: TLS handshake error from 10.1.3.1:43112: EOF
I0417 14:11:26.847464       1 logs.go:41] http: TLS handshake error from 10.1.3.1:43114: tls: first record does not look like a TLS handshake

[1] 
# oadm prune images --keep-tag-revisions=3 --keep-younger-than=60m --confirm --certificate-authority=/etc/origin/master/ca.crt
error: error communicating with registry: Get http://172.30.74.39:5000/healthz: malformed HTTP response "\x15\x03\x01\x00\x02\x02"
# oadm prune images --keep-tag-revisions=3 --keep-younger-than=60m --confirm --certificate-authority=/etc/origin/master/ca.crt --registry-url=172.30.74.39:5000
error: error communicating with registry: Get http://172.30.74.39:5000/healthz: malformed HTTP response "\x15\x03\x01\x00\x02\x02"

Version-Release number of selected component (if applicable):
$ oc version
oc v3.4.1.10
kubernetes v1.4.0+776c994
features: Basic-Auth GSSAPI Kerberos SPNEGO
 
Server https://osftmstr.dev.bmocm.com:8443
openshift v3.4.1.10
kubernetes v1.4.0+776c994

$ oadm version
oadm v3.4.1.10
kubernetes v1.4.0+776c994
 
Server https://osftmstr.dev.bmocm.com:8443
openshift v3.4.1.10
kubernetes v1.4.0+776c994

$ oc get dc -n default -o jsonpath='{range .items[*]}{"DC: "}{.metadata.name}{"\n Image:"}{.spec.template.spec.containers[*].image}{"\n"}{end}'
DC: docker-registry
 Image:registry.access.redhat.com/openshift3/ose-docker-registry:v3.4.1.10

Additional info:
We collected logs from the master services, docker-registry pod, and the info generated by adding --loglevel=8 to the prune command from before the attempt to add ca and url flags, will attach them shortly.