Fixes for Live mode, Linux and Firebird 3 compatibility

[qweqq]

Hello!

I found some bugs while trying to run the tool against Firebird 3 on Linux in Live mode - with the fixes in this pull request it seems to work with a production server with the same environment.

I wasn't sure if I should create separate pull requests so I created only one to keep the conversation in one place.

[cincuranet]

Hi. Thanks for the contribution. It would be better to create separate PRs. It's easier to manage.