thumbnail format is incorrect

[shc261392]

Steps to Reproduce

https://logboard-dev.numbersprotocol.io/api/v1/records/summary/?uid=39e8e6ad-ea65-4685-bfc4-454a6f809006&template=heartFailure&start_date=2020-01-01&end_date=2021-01-01

(This link is made semi-permanent and will not be deleted after 3 days)

Results

• Expected: The thumbnail field should be a list of list to represent the thumbnail list of each day
• Actual: The thumbnail field is a list of list of list

Logs

• See the above link

Environment

• logboard: ae25767 (v0.5.3)