Cannot Change Username

Changing username causes the application to crash. This bug does not affect the to be released version 1.8.2 but is not present in the already released version 1.8.1.

The method IsdsWrapper::getAccountDbId() expects the user account to be already logged in.

https://gitlab.labs.nic.cz/datovka/mobile-datovka/blob/develop/src/net/isds_wrapper.cpp#L338

The methods then returns an empty string which causes Accounts::changeAccountUserName() to cras when calling boxMatchesUser().