Update net-kourier nightly (#13273)
Update net-kourier nightly (#13273)

bumping knative.dev/net-kourier 9391054...4a13673:
  > 4a13673 Tests for encryption with Kourier local gateway (# 909)

Signed-off-by: Knative Automation <f415700d4d0ce1c81810fe7553e3eea2bed16231@knative.team>

Signed-off-by: Knative Automation <f415700d4d0ce1c81810fe7553e3eea2bed16231@knative.team>
knative/serving,knative/serving