Trailing spaces in directory names in Mac/Linux causes mods to fail to load.

[atravita-mods]

Describe the bug
Mac and Linux allow trailing spaces in folder names, but SMAPI does not.

To Reproduce

1. Download any mod on Mac or Linux.
2. Edit the directory of the mod so it ends with a trailing space
3. Try to launch the game.

Log file
Example mac log: https://smapi.io/log/9c0827a89d7c45bd805ad8af1eba4662