WHMCS isfinnish parameter is missing when sending Modify Contact Details form request

[teliarokaspaulikas]

EPP Request XML is required to have contact:isfinnish according to the https://registry.domain.fi/s/docs/EPP_Rajapintakuvaus.pdf

contact:isfinnish parameter value that is required and must be either 0 or 1 is not added to the final EPP Request XML, so with the response comes Error 2003: Required parameter missing: isfinnish is null.

Steps reproduce this bug in WHMCS:

1. Registrar Commands -> Modify Contact Details -> Select Use Following Details
2. Fill the required info and submit the form
3. You will get Registrar Error _Error 2003: Required parameter missing: isfinnish is null