fix panic, wrong logic
fix panic, wrong logic

Signed-off-by: splashx <326d177fc0fd78f79f4fbbf7f3d30fe1ab420c0c@gmail.com>

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