README: update link to docker images to quay.io
README: update link to docker images to quay.io

Signed-off-by: Gilberto Bertin <e45dca12016e9fd4d68d2c7903502c5e1a1f4f1b@isovalent.com>

tklauser/cilium,michi-covalent/cilium,michi-covalent/cilium,michi-covalent/cilium,michi-covalent/cilium,cilium/cilium,tklauser/cilium,tklauser/cilium,tklauser/cilium,cilium/cilium,cilium/cilium,michi-covalent/cilium,cilium/cilium,cilium/cilium,tklauser/cilium