Frontend not starting scanner with empty database

[GamingGuy003]

Describe the bug
If the database is empty, the frontend will display a confirmation dialgo on scan start. Regardles what is clicked, the scanner will not actually start and the frontend throws an error

To Reproduce
Steps to reproduce the behavior:
delete signatures.db, restart raspirus, start scan

Expected behavior
Scanner gets started even with no hashes in db

[Benji377]

This could be an issue with the parseInt function trying to parse a value that has not bee initialized (see #787 comments). This issue is affected by the lines here.
I could solve it by checking the variable before parsing it. I will keep this in mind when reworking the frontend.
For now, the same temporary solution applies as in #787

[Benji377]

This is no longer being checked with the new UI in Rust. One can now scan with an empty database