lnrpc: split walletunlocker in own file

lnrpc/gen_protos.sh

@@ -6,19 +6,19 @@ echo "Generating root gRPC server protos"
 protoc -I/usr/local/include -I. \
        -I$GOPATH/src/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis \
        --go_out=plugins=grpc,paths=source_relative:. \
-       rpc.proto
+       rpc.proto walletunlocker.proto
 
 # 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,paths=source_relative:. \
-       rpc.proto
+       rpc.proto walletunlocker.proto
 
 # Finally, generate the swagger file which describes the REST API in detail.
 protoc -I/usr/local/include -I. \
        -I$GOPATH/src/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis \
        --swagger_out=logtostderr=true:. \
-       rpc.proto
+       rpc.proto walletunlocker.proto
 
 # For each of the sub-servers, we then generate their protos, but a restricted
 # set as they don't yet require REST proxies, or swagger docs.