Changing a single letter in the path attempts loading that directory

[Cassidy James Blaede]

To reproduce:
- Open Marlin
- Navigate to a directory
- Try to modify a folder name in the path above the current directory

Expected outcome:
- You can type the modifications, then hit enter to load it

Actual outcome:
- Marlin tries loading the directory after each keystroke

[Cassidy James Blaede (cassidyjames)]

Here's a little video demonstrating it. I never hit Enter.

[Cassidy James Blaede (cassidyjames)]

After testing this a bit more, it seems the cause is that it's checking for a "/" on every keystroke. Even though a "/" exists, it doesn't mean I just typed it. :P