settings: skip unconfigured values
When a value is not configured in settings map, it is skipped.
If it is the last processed value, the result of ISC_R_NOTFOUND
would cause the cleanup section of the function fail. Since
unconfigured values are allowed and expected, override the result
to ISC_R_SUCCESS in this case to prevent triggerring an error.
https://pagure.io/bind-dyndb-ldap/issue/172
Reviewed-By: Martin Basti <mbasti@redhat.com>