Do not use ldap3 from Debian
The image for 4.8 uses the ldap3 package but it is broken see https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=905757
The image for 4.8 uses the ldap3 package but it is broken see https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=905757