(ITS#8434) Config entry cleanup on Add should be run unconditionally

[okuznik@symas.com]

Full_Name: Ondrej Kuznik
Version: master
OS: 
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (2a02:c7f:221f:c00:a3e:8eff:fe52:dac5)


With cn=config the ConfigLDAPadd function might have to allocate resources that
are needed by the time the attributes/config directives are being processed
since there is no indication which directives there are and what order they come
in.

If any of the config values fail validation, the configuration code has to react
and clean up - which is possible using ca->cleanup.

While Modify handling (config_modify_internal) already calls ca->cleanup in each
case, this is not true for config_add_internal, there it is only run on success.