Proto file registration panic on startup

[torkelrogstad]

I'm integrating Faraday into an application that communicates with gRPC, and I'm running into issues when importing the generated Faraday Go code: panic: proto: file "rpc.proto" is already registered. See this related issue on the golang/protobuf tracker: golang/protobuf#1122.

This is the line that panics:
https://github.com/lightninglabs/faraday/blob/master/frdrpc/rpc.pb.go#L1630

I'm no expert on technicalities of Protobuf/gRPC, but I see that other Go sources I'm using that's compiled from Proto files don't have the problematic reigstration function. These Go sources are compiled with a newer gRPC stack, specifically protoc-gen-go 1.25.0 and protoc 3.13.0. Could it be that compiling the Faraday Go sources with the newer gRPC stack would solve this?

The only real workaround right now is setting an environment variable, and I would have to make sure that this environment variable is properly set on all developer machines, production machines and CI systems. Sounds like a hassle...

[guggero]

I think the main issue here is that the rpc.proto has the same name as lnd's rpc.proto. A simple fix would be to rename it. Also updating the grpc library to the same version we now use in lnd should turn the panic into a warning.
@carlaKC do you have time to look at this?

[carlaKC]

Yeah will pick this up!

[torkelrogstad]

Closed in #110