Previously the object-expirer would not respect an internal_client_conf_path option if its config was loaded from a "legacy" config filepath (e.g. **/object-expirer.conf). Legacy object-expirer config expected config sections for an internal-client to be included in the same file. However, "modern" object-expirer config files (e.g. **/object-server.conf) expect internal-client config to be loaded from a separate file specified by internal_client_conf_path and defaulting to 'internal_client_conf_path'.
"Legacy" expirer config is still used in production clusters but it is useful to use a shared internal-client config. This patch therefore makes the internal_client_conf_path option always be respected regardless of the path of the object-expirer conf file. If 'internal_client_conf_path' is not specified, "modern" config will continue to use the default '/etc/swift/internal-client.conf', but "legacy" config will default to the path of the expirer conf file (i.e. the same as the previous behavior).
Related-Change: Ib21568f9b9d8547da87a99d65ae73a550e9c3230
Change-Id: I24ec702cd2ed074ca9df084cefc896418cece394
ee80f99aec