Handle nil response

[anton-putau]

I am trying to get response from lua function and got exception with nil value (lua function result):

var data = (await this.box.Call<TInput, TOutput>("FunctionName", Tuple.Create(.....))).Data;
Exception:

System.ArgumentException : Invalid array length: 3 is expected, but got 1. at Tarantool.Client.LogicalConnection.<SendRequestImpl>d__112.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Tarantool.Client.LogicalConnection.<SendRequest>d__72.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Tarantool.Client.Box.<Call>d__82.MoveNext()

Expected behavior Data = empty array

[aensidhe]

Won't fix. Nils in lua are broken.

msgpack.NULL