Voilà ce que j'ai dans mon httpd.conf

User webuser
Group webgroup

et dans /etc/passwd et /etc/group
debian:/home/lami20j# grep web /etc/{passwd,group}
/etc/passwd:webuser:x:50005:50005::/home/webuser:/bin/false
/etc/group:webgroup:x:50005:
et le daemon httpd lami20j@debian:~$ ps aux | grep httpd
root 3150 0.0 0.2 14248 564 ? Ss 09:49 0:00 /usr/local/httpd/bin/httpd -k start
webuser 3157 0.0 0.3 19152 800 ? S 09:49 0:00 /usr/local/httpd/bin/httpd -k start
webuser 3158 0.0 0.3 19152 800 ? S 09:49 0:01 /usr/local/httpd/bin/httpd -k start
webuser 3159 0.0 0.3 19036 796 ? S 09:49 0:00 /usr/local/httpd/bin/httpd -k start
webuser 3160 0.0 0.3 19020 796 ? S 09:49 0:00 /usr/local/httpd/bin/httpd -k start
webuser 3161 0.0 0.3 18728 820 ? S 09:49 0:01 /usr/local/httpd/bin/httpd -k start
webuser 9547 0.0 0.3 18420 796 ? S 10:28 0:00 /usr/local/httpd/bin/httpd -k start
webuser 9551 0.0 0.3 19104 800 ? S 10:28 0:00 /usr/local/httpd/bin/httpd -k start