net.box: backward compatibility with vshard async calls is broken

[olegrok]

tarantool> _TARANTOOL
---
- 2.10.0-beta1-13-gea192ca48-r438-macos
...

tarantool> vshard.router.callrw(1, 'echo', {1}, {is_async = true}):wait_result()
---
- [true, 1, null, null]
...

tarantool> echo = function(...) return ... end
---
...

tarantool> vshard.router.callrw(1, 'echo', {1}, {is_async = true}):wait_result()
---
- [1]
...
tarantool> _TARANTOOL
---
- 2.8.2-0-gfc96d10f5-r436-macos
...

BTW, if it's vshard problem feel free to transfer this issue to corresponding repo.

[Gerold103]

It was fixed in the latest vshard. Try 0.1.19. tarantool/vshard#294

[olegrok]

Yes, thanks. I'm completely forgot about this issue. It seems to work fine after update.