根据keyspace获取databases num时，需要加1

sql/engines/redis.py

@@ -70,7 +70,7 @@ def get_all_databases(self, **kwargs):
                 for i in conn.info("Keyspace").keys()
                 if len(i.split("db")) == 2
             ]
-            rows = max(dbs + [16])
+            rows = max(dbs + [15]) + 1
 
         db_list = [str(x) for x in range(int(rows))]
         result.rows = db_list