clientv3: Fix URL to rpc errors
@@ -44,7 +44,7 @@
// etcd client returns 2 types of errors:
//
// 1. context error: canceled or deadline exceeded.
-// 2. gRPC error: see https://github.com/coreos/etcd/blob/master/etcdserver/api/v3rpc/error.go.
+// 2. gRPC error: see https://github.com/coreos/etcd/blob/master/etcdserver/api/v3rpc/rpctypes/error.go
// Here is the example code to handle client errors: