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

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.