restore: Fix incorrect fallback case

When the updated behavior is not triggered, the legacy behavior must be correctly executed. Thus, always correctly fall back to old behavior instead of aborting here.

For example message can be NULL when restoring iOS 1.0 (in my fork).

src/restore.c

@@ -650,9 +650,9 @@ typedef struct restore_service_client {
 
 static void* _restore_get_service_client_for_data_request(struct idevicerestore_client_t *client, plist_t message)
 {
-	if (!client || !client->restore || !client->restore->client || !PLIST_IS_DICT(message)) return NULL;
+	if (!client || !client->restore || !client->restore->client) return NULL;
 	restore_service_client_t service = (restore_service_client_t)malloc(sizeof(struct restore_service_client));
-	if (!plist_dict_get_item(message, "DataPort")) {
+	if (!PLIST_IS_DICT(message) || !plist_dict_get_item(message, "DataPort")) {
 		service->client = client->restore->client;
 		service->type = SERVICE_TYPE_RESTORED;
 		return service;