Safety logic or better UX when adding new sync directories

[kugiigi]

Description

I'm not sure exactly how it happened but I accidentally added my whole NC to sync on my device. I was trying to add a single directory and if I remember correctly, I tried to enter the name/label multiple times. When is the sync actually added anyway? What happened to me is that a correct entry was added but also another one with empty target NC directory and I guess it treated that as the root NC directory.