Fix to read config.toml at tui

[usiusi360]

What did you implement:

Closes #396, #439

How did you implement it:

At tui, did not load config.toml.
I fixed it.

How can we verify it:

./vuls tui

Todos:

• Write tests
• Write documentation
• Check that there aren't other open pull requests for the same issue/feature
• Format your source code by make fmt
• Pass the test by make test
• Provide verification config / commands
• Enable "Allow edits from maintainers" for this PR
• Update the messages below

Is this ready for review?: YES
Is it a breaking change?: NO

[kotakanbe]

LGTM