fix get_accounts isssue #1734

[oxarbitrage]

#1734

@abitmore let me know what do you think about this before i add similar code into get_assets.

Thank you.

$ curl --silent -d '{"id":1,"method":"call","params":["database","get_accounts",[["unexisting-account-should-return-null"]]]}' http://127.0.0.1:8090/ws | jq
{
  "id": 1,
  "jsonrpc": "2.0",
  "result": [
    null
  ]
}
$

[abitmore]

Yes, this is what I want, although IMHO the parameter name should_throw is a bit confusing.

Please check all related APIs with a vector in parameter list. Thanks.

• get_accounts
• get_full_accounts
• get_assets

[oxarbitrage]

Please note get_full_accounts will return empty result instead of null if the account does not exist.

get_accounts and get_assets will return null.