acmesolver: Run as non-root
acmesolver: Run as non-root

acmesolver won't run in a namespace with a restrictive PSP
(Pod Security Policy)[1] without this change.
Note: A numeric user id is required due to [1]

[1] https://kubernetes.io/docs/concepts/policy/pod-security-policy/#users-and-groups
[2] https://github.com/kubernetes/kubernetes/pull/56503

jetstack-experimental/cert-manager,cert-manager/cert-manager,jetstack-experimental/cert-manager,jetstack-experimental/cert-manager,cert-manager/cert-manager,jetstack/cert-manager,cert-manager/cert-manager,jetstack/cert-manager,jetstack/cert-manager