test: flaky replication/wal_rw_stress.test.lua test on status check

[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 (CentOS 7)

Bug description:
https://gitlab.com/tarantool/tarantool/-/jobs/759812885#L6023

artifacts.zip

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

[048] --- replication/wal_rw_stress.result	Wed Aug 26 06:06:16 2020
[048] +++ replication/wal_rw_stress.reject	Mon Sep 28 03:16:57 2020
[048] @@ -77,7 +77,40 @@
[048]              r.downstream.status ~= 'stopped')    \
[048]  end) or box.info
[048]  ---
[048] -- true
[048] +- version: 2.6.0-115-ge19b392f0
[048] +  id: 2
[048] +  ro: false
[048] +  uuid: 63104370-9fc6-4162-b5ca-b2ae6be2e179
[048] +  package: Tarantool
[048] +  cluster:
[048] +    uuid: 55043ca8-d79b-4a89-8551-db0c0059a80e
[048] +  listen: unix/:/tmp/tnt/048_replication/replica.socket-iproto
[048] +  replication_anon:
[048] +    count: 0
[048] +  replication:
[048] +    1:
[048] +      id: 1
[048] +      uuid: 0eeabfcd-723f-4e1d-b0c2-bb820c3a6657
[048] +      lsn: 10636
[048] +      upstream:
[048] +        status: follow
[048] +        idle: 0.20655800029635
[048] +        peer: unix/:/tmp/tnt/048_replication/master.socket-iproto
[048] +        lag: 9.918212890625e-05
[048] +    2:
[048] +      id: 2
[048] +      uuid: 63104370-9fc6-4162-b5ca-b2ae6be2e179
[048] +      lsn: 0
[048] +  signature: 10636
[048] +  status: running
[048] +  vclock: {1: 10636}
[048] +  uptime: 61
[048] +  lsn: 0
[048] +  sql: []
[048] +  gc: []
[048] +  vinyl: []
[048] +  memory: []
[048] +  pid: 33722
[048]  ...
[048]  test_run:cmd("switch default")
[048]  ---
[048] 

Steps to reproduce:

Optional (but very desirable):

• coredump
• backtrace
• netstat