Returns data is inconsistent

[gutenye]

Test with https://api.tronscan.org/api/transaction?address=TRAqdc9Un9JWqPMYSQR7o7EU5vUUG8tBR1&token=TRX&date_start=1539938562001&limit=100&sort=timestamp

• Most of the time, it returns {"data":[]}, which is correct.
• Sometimes, it returns with {"id":"", "contractData":null } with the old transactions before the date_start.

[roccomuso]

I think date_start is deprecated. I replaced it with start_timestamp and the results look good.