test: flaky sql-tap/selectG.test.lua test

[avtikhon]

Tarantool version:
Tarantool 2.6.0-115-ge19b392f0
Target: Darwin-x86_64-RelWithDebInfo
Build options: cmake . -DCMAKE_INSTALL_PREFIX=/Users/tntmac04.tarantool.i/builds/PVWCJs8U/0/tarantool/tarantool/static-build/tarantool-prefix -DENABLE_BACKTRACE=TRUE
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:
Linux (Debian *)

Bug description:
https://gitlab.com/tarantool/tarantool/-/jobs/759554176#L4863

artifacts.zip

Not possible to use results file checksum due to different data in error message:

[122] sql-tap/selectG.test.lua                        memtx           
[122] not ok 1 - 100 #  
[122] Traceback:
[122] [Lua ] function 'do_test' at </builds/nZUxDh2c/0/tarantool/tarantool/test/var/122_sql-tap/sqltester.lua:120>
[122] [main] at </builds/nZUxDh2c/0/tarantool/tarantool/test/sql-tap/selectG.test.lua:0>
[122] 
[122] Rejected result file: sql-tap/selectG.reject
[122] [ fail ]

Steps to reproduce:

Optional (but very desirable):

• coredump
• backtrace
• netstat

[Buristan]

Duplicate of #294.