`create_from_pkcs12` method of CertDB was re-creating NSS database files during PKCS#12 bundle import. This may cause bugs because the file permissions could be re-set to wrong values causing subtle bugs. Modify the class API so that the server cert chain can be imported while preserving existing FS attributes. https://fedorahosted.org/freeipa/ticket/6429 Reviewed-By: Jan Cholasta <jcholast@redhat.com>