test: flaky net.box_on_schema_reload-gh-1904.test.lua test

[avtikhon]

Tarantool version:
Tarantool 2.6.0-114-g6c0468756
Target: Darwin-x86_64-RelWithDebInfo
Build options: cmake . -DCMAKE_INSTALL_PREFIX=/usr/local -DENABLE_BACKTRACE=ON
Compiler: /Library/Developer/CommandLineTools/usr/bin/cc /Library/Developer/CommandLineTools/usr/bin/c++
C_FLAGS: -Wno-unknown-pragmas -fexceptions -funwind-tables -fno-omit-frame-pointer -fno-stack-protector -fno-common -msse2 -std=c11 -Wall -Wextra -Wno-strict-aliasing -Wno-char-subscripts -Wno-gnu-alignof-expression -Werror
CXX_FLAGS: -Wno-unknown-pragmas -fexceptions -funwind-tables -fno-omit-frame-pointer -fno-stack-protector -fno-common -msse2 -std=c++11 -Wall -Wextra -Wno-strict-aliasing -Wno-char-subscripts -Wno-invalid-offsetof -Wno-gnu-alignof-expression -Werror

OS version:
OSX 14

Bug description:
https://gitlab.com/tarantool/tarantool/-/jobs/759177772#L4426

artifacts.zip

results file checksum: cf81a7329eaf70938dabe1a58d3c3bbd

[015] --- box/net.box_on_schema_reload-gh-1904.result	Sat Sep 12 18:54:37 2020
[015] +++ box/net.box_on_schema_reload-gh-1904.reject	Sun Sep 27 01:51:20 2020
[015] @@ -70,7 +70,8 @@
[015]      return a
[015]  end;
[015]  ---
[015] -- 2
[015] +- error: '[string "do     local a = 0     function osr_cb()     ..."]:1: attempt to
[015] +    index field ''space'' (a nil value)'
[015]  ...
[015]  do
[015]      local a = 0
[015] @@ -91,7 +92,8 @@
[015]      return a
[015]  end;
[015]  ---
[015] -- 1
[015] +- error: '[string "do     local a = 0     function osr_cb()     ..."]:1: attempt to
[015] +    index field ''space'' (a nil value)'
[015]  ...
[015]  test_run:cmd("setopt delimiter ''");
[015]  ---
[015] 

Steps to reproduce:

Optional (but very desirable):

• coredump
• backtrace
• netstat