Remove previously deprecated rprotoc executable
Remove previously deprecated rprotoc executable

Use `protoc —ruby_out` instead.

zanker/protobuf,brianstien/protobuf,film42/protobuf,quixoten/protobuf,localshred/protobuf,zanker/protobuf,ruby-protobuf/protobuf,lookout/protobuffy,localshred/protobuf,ruby-protobuf/protobuf,brianstien/protobuf,lookout/protobuffy,film42/protobuf,quixoten/protobuf