Fix link (#453)

Signed-off-by: Ofek Lev <[email protected]>

README.md

@@ -33,7 +33,7 @@ A complete Raft model contains 4 essential parts:
 
 ## Using the raft crate
 
-You can use raft with either [rust-protobuf](https://github.com/pingcap/rust-protobuf) or [Prost](https://github.com/danburkert/prost) to encode/decode gRPC messages. We use rust-protobuf by default. To use Prost, build (or depend on) Raft using the `prost-codec` feature and without default features.
+You can use raft with either [rust-protobuf](https://github.com/pingcap/rust-protobuf) or [Prost](https://github.com/tokio-rs/prost) to encode/decode gRPC messages. We use rust-protobuf by default. To use Prost, build (or depend on) Raft using the `prost-codec` feature and without default features.
 
 ## Developing the Raft crate