test: flaky box/access_misc.test.lua test

[avtikhon]

Tarantool version:
Tarantool 2.6.0-141-g83fb85c21
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 15

Bug description:
https://gitlab.com/tarantool/tarantool/-/jobs/771303614#L3967

artifacts.zip

results file checksum: da9f6f9172f41083d8ae3eda3565a58e

[029] --- box/access_misc.result	Fri Oct  2 17:34:50 2020
[029] +++ box/access_misc.reject	Sat Oct  3 23:45:08 2020
[029] @@ -802,4 +802,5 @@
[029]  ...
[029]  box.schema.user.drop('tester')
[029]  ---
[029] -...
[029] +- error: Unsupported role privilege '4'
[029] +...
[029] 

Steps to reproduce:

Optional (but very desirable):

• coredump
• backtrace
• netstat