Fix error string capitalization
Fix error string capitalization

pkg/issuer/acme/dns/akamai/akamai.go:205:15: error strings should not be capitalized (ST1005)

Signed-off-by: Richard Wall <c2866c0eefadc742fd429365a658dfba4f801ca3@jetstack.io>

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