[TD-6635]<test>:modify python file about ts = 1600000**

tests/pytest/query/nestquery_last_row.py

@@ -17,6 +17,7 @@ from util.log import tdLog
 from util.cases import tdCases
 from util.sql import tdSql
 import random
+import time
 
 
 class TDTestCase:
@@ -24,7 +25,8 @@ class TDTestCase:
         tdLog.debug("start to execute %s" % __file__)
         tdSql.init(conn.cursor(), logSql)
 
-        self.ts = 1600000000000
+        now = time.time()
+        self.ts = int(round(now * 1000))
         self.num = 10
 
     def run(self):