The github version of the user_ldap still needs to be taken with care because of this statement:
Please also note that the user_ldap is currently under a major rework and a new improved version should be available in 3-4 weeks.
→ ownCloud causes 100% CPU on LDAP(samba4)-Server - #2 by Kawohl
If you heavily rely on the user_ldap then you might need to consider to revert to your oC 9.1.5 backup for now.