update timetruncate.py

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

@@ -21,7 +21,6 @@ class TDTestCase:
         self.db_param_precision = ['ms','us','ns']
         self.time_unit = ['1w','1d','1h','1m','1s','1a','1u','1b']
         self.error_unit = ['2w','2d','2h','2m','2s','2a','2u','1c','#1']
-        self.error_unit = ['2w','2d','2h','2m','2s','2a','2u','1c','#1']
         self.ntbname = 'ntb'
         self.stbname = 'stb'
         self.ctbname = 'ctb'