Uncrustify is being treated as non-optional dependency

[Tbusk]

Describe the bug For a while, when creating a file, my IDE kept throwing an error from the language server saying

textDocument/formatting
Formatting failed: Failed to execute child process ?uncrustify? (No such file or directory)

Which when creating a file, you'd think it would be something specifically related to the project and some disconnect happening since my plugin is new.

The actual issue that is arising is that uncrustify is being treated as a non-optional dependency. When not installed, that error message is showing up. When installed, it does not show up.

The README.md says that uncrustify is optional. Perhaps the optional portion should be taken out?

Software OS and version (e.g. Ubuntu 20.04): Elementary OS Code editor (e.g. VSCode): Jetbrains IDEs Vala Language Server (e.g. git commit, or PPA/AUR version): latest Vala version (valac --version): latest

To Reproduce Steps to reproduce the behavior:

1. Create a vala source file without that dependency installed