Fix for this has already been verified on version 4.5, for 4.4 we are still awaiting for cherry-pick approval, moving it to the next sprint.
Verified on 4.4.0-0.nightly-2020-06-03-225439:
# configs.imageregistry.operator.openshift.io "cluster" was not valid:
# * spec.storage.azure.container: Invalid value: "": spec.storage.azure.container in body should match '^[0-9a-z]+(-[0-9a-z]+)*$'
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.