MT#55283 use more appropriate helper function

The string might not be null terminated.

Change-Id: I09d64d69202c8ce7196b8d39223d785353fbd4eb

daemon/redis.c

@@ -2111,7 +2111,7 @@ static void json_restore_call(struct redis *r, const str *callid, bool foreign)
 	redis_hash_get_time_t(&c->deleted, &call, "deleted");
 	redis_hash_get_time_t(&c->ml_deleted, &call, "ml_deleted");
 	if (!redis_hash_get_str(&id, &call, "created_from"))
-		c->created_from = call_strdup(id.s);
+		c->created_from = call_strdup_str(&id);
 	if (!redis_hash_get_str(&id, &call, "created_from_addr")) {
 		if (sockaddr_parse_any_str(&c->created_from_addr, &id))
 			goto err8;