server: more constness in server.cc (#7645)
server: more constness in server.cc (#7645)

Risk LeveL :low
Testing: existing
Doc Changes: n/a
Release Notes: n/a

Signed-off-by: Raul Gutierrez Segales <f25f6873bbbde69f1fe653b3e6bd40d543b8d0e0@pinterest.com>
eklitzke/envoy,envoyproxy/envoy-wasm,lyft/envoy,eklitzke/envoy,envoyproxy/envoy,lizan/envoy,jrajahalme/envoy,jrajahalme/envoy,envoyproxy/envoy,jrajahalme/envoy,lizan/envoy,envoyproxy/envoy-wasm,istio/envoy,lyft/envoy,envoyproxy/envoy,jrajahalme/envoy,envoyproxy/envoy-wasm,eklitzke/envoy,istio/envoy,istio/envoy,envoyproxy/envoy,envoyproxy/envoy,lizan/envoy,lyft/envoy,lyft/envoy,eklitzke/envoy,lyft/envoy,envoyproxy/envoy-wasm,lizan/envoy,envoyproxy/envoy,envoyproxy/envoy,istio/envoy,envoyproxy/envoy,lyft/envoy,lizan/envoy,envoyproxy/envoy,envoyproxy/envoy-wasm,istio/envoy,jrajahalme/envoy,eklitzke/envoy,envoyproxy/envoy,envoyproxy/envoy-wasm,istio/envoy,istio/envoy,envoyproxy/envoy-wasm,lizan/envoy,envoyproxy/envoy,envoyproxy/envoy,eklitzke/envoy,jrajahalme/envoy