Sometimes get: terminate called after throwing an instance of 'std::logic_error'

[lbt]

The following error occurs when there's a dangling symlink in the tree being watched:

terminate called after throwing an instance of 'std::logic_error'
what(): Could not stat file of unknown type
Aborted

This PR fixes it for me:
#9

The repo seems quite inactive so maybe this issue/PR will help someone else :)