license: update NOTICE to switch to CNCF copyright (#2663)
license: update NOTICE to switch to CNCF copyright (#2663)

Signed-off-by: Matt Klein <684e4e870ef5a243d6d0345280f09d95db603639@lyft.com>
jrajahalme/envoy,envoyproxy/envoy-wasm,craffert0/envoy,envoyproxy/envoy,jrajahalme/envoy,dnoe/envoy,lyft/envoy,eklitzke/envoy,jrajahalme/envoy,lizan/envoy,envoyproxy/envoy,eklitzke/envoy,envoyproxy/envoy,lyft/envoy,sebrandon1/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy-wasm,lizan/envoy,istio/envoy,envoyproxy/envoy,istio/envoy,istio/envoy,envoyproxy/envoy,sebrandon1/envoy,envoyproxy/envoy,envoyproxy/envoy-wasm,jrajahalme/envoy,jrajahalme/envoy,sebrandon1/envoy,envoyproxy/envoy,lyft/envoy,istio/envoy,envoyproxy/envoy-wasm,envoyproxy/envoy-wasm,dnoe/envoy,lizan/envoy,dnoe/envoy,dnoe/envoy,sebrandon1/envoy,lizan/envoy,istio/envoy,lizan/envoy,eklitzke/envoy,envoyproxy/envoy,craffert0/envoy,lyft/envoy,craffert0/envoy,envoyproxy/envoy-wasm,sebrandon1/envoy,dnoe/envoy,envoyproxy/envoy,istio/envoy,eklitzke/envoy,lizan/envoy,eklitzke/envoy,istio/envoy,lyft/envoy,jrajahalme/envoy,envoyproxy/envoy-wasm,craffert0/envoy,lyft/envoy,eklitzke/envoy,envoyproxy/envoy