proto: update to grpc-gateway v1.8.6

lnrpc/README.md

@@ -170,11 +170,11 @@ $ cd $GOPATH/src/google.golang.org/genproto
 $ git reset --hard a8101f21cf983e773d0c1133ebc5424792003214
 ```
 
-4. Install `grpc-ecosystem/grpc-gateway` at commit `f2862b476edcef83412c7af8687c9cd8e4097c0f`.
+4. Install `grpc-ecosystem/grpc-gateway` at version `v1.8.6`.
 ```bash
 $ git clone https://github.com/grpc-ecosystem/grpc-gateway $GOPATH/src/github.com/grpc-ecosystem/grpc-gateway
 $ cd $GOPATH/src/github.com/grpc-ecosystem/grpc-gateway
-$ git reset --hard f2862b476edcef83412c7af8687c9cd8e4097c0f
+$ git reset --hard v1.8.6
 $ go install ./protoc-gen-grpc-gateway ./protoc-gen-swagger
 ```
 

lnrpc/gen_protos.sh

@@ -11,7 +11,7 @@ protoc -I/usr/local/include -I. \
 # Generate the REST reverse proxy.
 protoc -I/usr/local/include -I. \
        -I$GOPATH/src/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis \
-       --grpc-gateway_out=logtostderr=true:. \
+       --grpc-gateway_out=logtostderr=true,paths=source_relative:. \
        rpc.proto
 
 # Finally, generate the swagger file which describes the REST API in detail.