Internal server error is returned for invalid DAO for /api/v1/tokens/account-tokens endpoint

[roman-ponomarenko]

STR:

1. Send a request to get a list of tokens for invalid DAO
   https://api.dev.app.astrodao.com/api/v1/tokens/account-tokens/ttwyeyw.testnet

AR:
Internal server error is returned

ER:
Empty array or valid error message is returned