Properly fix prev/next in set.

models/Asset.php

@@ -515,12 +515,12 @@ class Asset
 			INNER JOIN assets AS a ON a.id_asset = t.id_asset
 			WHERE t.id_tag = {int:id_tag} AND
 				a.date_captured <= {datetime:date_captured} AND
-				a.id_asset != {int:id_asset}
+				a.id_asset <= {int:id_asset}
 			ORDER BY a.date_captured DESC'
 			: '
 			FROM assets AS a
 			WHERE date_captured >= {datetime:date_captured} AND
-				a.id_asset != {int:id_asset}
+				a.id_asset >= {int:id_asset}
 			ORDER BY date_captured ASC')
 			 . '
 			LIMIT 1',