Update generated natdiscovery.pb.go
The protobuf code generation CI job is failing without
this change.
It seems the protoc-gen-go version was bumped somewhere.
// Code generated by protoc-gen-go. DO NOT EDIT.
// versions:
-// protoc-gen-go v1.26.0-devel
+// protoc-gen-go v1.27.0-devel
// protoc v3.17.3
// source: pkg/natdiscovery/proto/natdiscovery.proto
