* dirmngr/http.h (struct http_redir_info_s): Add restrict_redir.
* dirmngr/ks-engine-hkp.c (send_request): Set it depending on flags.
* dirmngr/ks-engine-http.c (ks_http_fetch): Ditto.
* dirmngr/t-http-basic.c (test_http_prepare_redirect): Always set it.
* dirmngr/http.c (http_prepare_redirect): Remove location rewriting
unless the flag is set.