PAM/LDAP authentication for webmin

In order to make it work, I have the following lines in /etc/webmin/miniserv.conf, which means it allows all unix users of admin group to login to webmin with their PAM password and act as root user of webmin or all unix users of user group to login with their PAM password and act as dnsmasq user of webmin.
unixauth=@admin=root @user=dnsmasq
pam=webmin

The following line in /etc/webmin/miniserv.users defines users of webmin (two users defined with name root and dnsmasq)
root:x:0::::::::
dnsmasq:x:0:::::::0:

The following lines in /etc/pam.d/webmin provides LDAP authentication for PAM password
auth sufficient pam_ldap.so
auth include system-auth

account sufficient pam_ldap.so
account required pam_nologin.so
account include system-auth

password required pam_ldap.so
password include system-auth

session sufficient pam_ldap.so
session include system-auth