BUG/MINOR: http: Memory leak of http redirect rules' format string

When the configuration contains such a line:
    http-request redirect location /
a "struct logformat_node" object is created and it contains an "arg"
member which gets alloc'ed as well in which we copy the new location
(see add_to_logformat_list). This internal arg pointer was not freed in
the dedicated release_http_redir release function.
Likewise, the expression pointer was not released as well.

This patch can be backported to all stable branches. It should apply
as-is all the way to 2.2 but it won't on 2.0 because release_http_redir
did not exist yet.

(cherry picked from commit 3120284c29f8f4c25458c432c544786657e5db26)
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit fe5f84ae3eddbfbb34b1fd9b08b50c6246358279)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>

src/http_act.c

@@ -1769,6 +1769,8 @@ static void release_http_redir(struct act_rule *rule)
 	free(redir->cookie_str);
 	list_for_each_entry_safe(lf, lfb, &redir->rdr_fmt, list) {
 		LIST_DELETE(&lf->list);
+		release_sample_expr(lf->expr);
+		free(lf->arg);
 		free(lf);
 	}
 	free(redir);

src/proxy.c

@@ -243,6 +243,8 @@ void free_proxy(struct proxy *p)
 		free(rdr->rdr_str);
 		list_for_each_entry_safe(lf, lfb, &rdr->rdr_fmt, list) {
 			LIST_DELETE(&lf->list);
+			release_sample_expr(lf->expr);
+			free(lf->arg);
 			free(lf);
 		}
 		free(rdr);