Fix corner-case check when testing joins of a single ".". (#9703)
Fix corner-case check when testing joins of a single ".". (#9703)

Signed-off-by: Joshua Marantz <c3f6b7d9de5243f9f0884ee043fd42ff9df5f177@google.com>
istio/envoy,jrajahalme/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,lyft/envoy,lyft/envoy,lizan/envoy,lyft/envoy,eklitzke/envoy,envoyproxy/envoy-wasm,envoyproxy/envoy,envoyproxy/envoy,eklitzke/envoy,lizan/envoy,lizan/envoy,envoyproxy/envoy,jrajahalme/envoy,eklitzke/envoy,istio/envoy,lyft/envoy,istio/envoy,istio/envoy,envoyproxy/envoy-wasm,envoyproxy/envoy-wasm,lizan/envoy,eklitzke/envoy,envoyproxy/envoy,eklitzke/envoy,envoyproxy/envoy,eklitzke/envoy,lizan/envoy,envoyproxy/envoy-wasm,lyft/envoy,lyft/envoy,jrajahalme/envoy,lizan/envoy,envoyproxy/envoy-wasm,envoyproxy/envoy-wasm,jrajahalme/envoy,istio/envoy,istio/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,jrajahalme/envoy,jrajahalme/envoy,envoyproxy/envoy,istio/envoy,envoyproxy/envoy-wasm