Hotfix/sangshuduo/td 5725 taosdump help timestamp for 2.0 (#7192)

* [TD-5725]<fix>: taosdump --help, regarding acceptable timestamp.

* make example date time same.

src/kit/taosdump/taosdump.c

@@ -231,8 +231,8 @@ static struct argp_option options[] = {
     {"schemaonly", 's', 0, 0,  "Only dump schema.", 2},
     {"without-property", 'N', 0, 0,  "Dump schema without properties.", 2},
     {"avro", 'V', 0, 0,  "Dump apache avro format data file. By default, dump sql command sequence.", 2},
-    {"start-time",    'S', "START_TIME",  0,  "Start time to dump. Either epoch or ISO8601/RFC3339 format is acceptable. ISO8601 format example: 2017-10-01T18:00:00.000+0800 or 2017-10-0100:00:00.000+0800 or '2017-10-01 00:00:00.000+0800'",  4},
-    {"end-time",      'E', "END_TIME",    0,  "End time to dump. Either epoch or ISO8601/RFC3339 format is acceptable. ISO8601 format example: 2017-10-01T18:00:00.000+0800 or 2017-10-0100:00:00.000+0800 or '2017-10-01 00:00:00.000+0800'",  5},
+    {"start-time",    'S', "START_TIME",  0,  "Start time to dump. Either epoch or ISO8601/RFC3339 format is acceptable. ISO8601 format example: 2017-10-01T00:00:00.000+0800 or 2017-10-0100:00:00:000+0800 or '2017-10-01 00:00:00.000+0800'",  4},
+    {"end-time",      'E', "END_TIME",    0,  "End time to dump. Either epoch or ISO8601/RFC3339 format is acceptable. ISO8601 format example: 2017-10-01T00:00:00.000+0800 or 2017-10-0100:00:00.000+0800 or '2017-10-01 00:00:00.000+0800'",  5},
 #if TSDB_SUPPORT_NANOSECOND == 1
     {"precision",  'C', "PRECISION",  0,  "Specify precision for converting human-readable time to epoch. Valid value is one of ms, us, and ns. Default is ms.", 6},
 #else