update case for duration for create db

tests/system-test/2-query/distribute_agg_max.py

@@ -39,7 +39,7 @@ class TDTestCase:
     def prepare_datas_of_distribute(self):
         
         # prepate datas for  20 tables distributed at different vgroups
-        tdSql.execute("create database if not exists testdb keep 3650 days 1000 vgroups 5")
+        tdSql.execute("create database if not exists testdb keep 3650 duration 1000 vgroups 5")
         tdSql.execute(" use testdb ")
         tdSql.execute(
             '''create table stb1

tests/system-test/2-query/max.py

@@ -93,7 +93,7 @@ class TDTestCase:
     def support_distributed_aggregate(self):
         
         # prepate datas for  20 tables distributed at different vgroups
-        tdSql.execute("create database if not exists testdb keep 3650 days 1000 vgroups 5")
+        tdSql.execute("create database if not exists testdb keep 3650 duration 1000 vgroups 5")
         tdSql.execute(" use testdb ")
         tdSql.execute(
             '''create table stb1