MEDIUM: http: The redirect strings follows the log format rules.

We handle "http-request redirect" with a log-format string now, but we
leave "redirect" unaffected.

Note that the control of the special "/" case is move from the runtime
execution to the configuration parsing. If the format rule list is
empty, the build_logline() function does nothing.
diff --git a/include/proto/proto_http.h b/include/proto/proto_http.h
index 7f58d7a..97e4652 100644
--- a/include/proto/proto_http.h
+++ b/include/proto/proto_http.h
@@ -117,8 +117,8 @@
 struct http_res_rule *parse_http_res_cond(const char **args, const char *file, int linenum, struct proxy *proxy);
 void free_http_req_rules(struct list *r);
 struct chunk *http_error_message(struct session *s, int msgnum);
-struct redirect_rule *http_parse_redirect_rule(const char *file, int line, struct proxy *curproxy,
-                                               const char **args, char **errmsg);
+struct redirect_rule *http_parse_redirect_rule(const char *file, int linenum, struct proxy *curproxy,
+                                               const char **args, char **errmsg, int use_fmt);
 
 /* to be used when contents change in an HTTP message */
 #define http_msg_move_end(msg, bytes) do { \