Update to v2.6.6 without release

- Fix a bug about purchase discount
- Fix a bug about database synchronization, which may make 'api_login' table empty
- For Arcaea 3.8.8
- Update a logout api

latest version/database/singles.json

@@ -790,4 +790,18 @@
 	}],
 	"orig_price": 100,
 	"price": 100
+}, {
+	"name": "redolentshape",
+	"items": [{
+		"type": "single",
+		"id": "redolentshape",
+		"is_available": true
+	}, {
+		"type": "core",
+		"amount": 1,
+		"id": "core_generic",
+		"is_available": true
+	}],
+	"orig_price": 100,
+	"price": 100
 }]