Supervisor socket error: Unlinking stale socket /tmp/supervisor.sock – Debian

I installed Supervisor on a shared Debian server. When I run:
supervisord -c supervisord.conf
I get this error continuously untill I kill it:Unlinking stale socket /tmp/supervisor.sock
When I run supervisorctl status I get:
unix:///tmp/supervisor.sock no such file
My supervisord.conf file like this (I didn`t change anything):

[unix_http_server]
file=/tmp/supervisor.sock     ; (the path to the socket file)
;chmod=0700                 ; socket file mode (default 0700)

[supervisord]
logfile=/tmp/supervisord.log ; (main log file;default $CWD/supervisord.log)
logfile_maxbytes=50MB        ; (max main logfile bytes b4 rotation;default 50MB)
logfile_backups=10           ; (num of main logfile rotation backups;default 10)
loglevel=info                ; (log level;default info; others: debug,warn,trace)
pidfile=/tmp/supervisord.pid ; (supervisord pidfile;default supervisord.pid)
nodaemon=false               ; (start in foreground if true;default false)
minfds=1024                  ; (min. avail startup file descriptors;default 1024)
minprocs=200                 ; (min. avail process descriptors;default 200)

[rpcinterface:supervisor]
supervisor.rpcinterface_factory = supervisor.rpcinterface:make_main_rpcinterface

[supervisorctl]
serverurl=unix:///tmp/supervisor.sock   ; use a unix:// URL  for a unix socket

[program:laravel-worker]
process_name=%(program_name)s_%(process_num)02d
command=php /path/to/app/artisan queue:work  --sleep=3 --tries=3
autostart=true
autorestart=true
;user=
numprocs=8
redirect_stderr=true
stdout_logfile= /path/to/app/worker.log

When I cd to /tmp to look for the socket file, the socket looks like this:
supervisor.sock.824804.
The six-digit number gets somehow generated randomly by the server after I run the supervisord -c supervisord.confcommand. Do I have to consider this six-digit in the supervisord.config file? And how to I do this, since it gets generated randomly? I have already installed and run Supervisor on a macOS Mojave too and there were no problemes and the socket file just locked like supervisor.sock. Thank for any help and suggestion in advance!