lnrpc: update grpc-gateway library to v2

lnrpc/gen_protos_docker.sh

@@ -5,12 +5,12 @@ set -e
 # Directory of the script file, independent of where it's called from.
 DIR="$(cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd)"
 
-PROTOC_GEN_VERSION=$(go list -f '{{.Version}}' -m github.com/golang/protobuf)
-GRPC_GATEWAY_VERSION=$(go list -f '{{.Version}}' -m github.com/grpc-ecosystem/grpc-gateway)
+PROTOBUF_VERSION=$(go list -f '{{.Version}}' -m google.golang.org/protobuf)
+GRPC_GATEWAY_VERSION=$(go list -f '{{.Version}}' -m github.com/grpc-ecosystem/grpc-gateway/v2)
 
 echo "Building protobuf compiler docker image..."
 docker build -t lnd-protobuf-builder \
-  --build-arg PROTOC_GEN_VERSION="$PROTOC_GEN_VERSION" \
+  --build-arg PROTOBUF_VERSION="$PROTOBUF_VERSION" \
   --build-arg GRPC_GATEWAY_VERSION="$GRPC_GATEWAY_VERSION" \
   .