[yabridgectl] Update to Rust 2021

Rust 1.58 will be released tomorrow, so now that Rust 2021 has been out
for two releases bumping this should be fine.

CHANGELOG.md

@@ -71,6 +71,7 @@ Versioning](https://semver.org/spec/v2.0.0.html).
 ### Packaging notes
 
 - We now target VST3 SDK version 3.7.4 with git tag `v3.7.4_build_25-patched`.
+- Yabridgectl now uses Rust 2021 and requires rustc 1.56 or newer to build.
 
 ## [3.7.0] - 2021-11-21
 

tools/yabridgectl/Cargo.toml

@@ -4,7 +4,7 @@ name = "yabridgectl"
 # there's not a lot going on here
 version = "3.7.0"
 authors = ["Robbert van der Helm <mail@robbertvanderhelm.nl>"]
-edition = "2018"
+edition = "2021"
 description = "Optional utility to help set up yabridge"
 repository = "https://github.com/robbert-vdh/yabridge"
 license = "GPL-3.0-or-later"

tools/yabridgectl/src/main.rs

@@ -142,7 +142,7 @@ fn main() -> Result<()> {
                             "symlink".bright_white()
                         ).as_ref())
                         .setting(clap::ArgSettings::NextLineHelp)
-                        .possible_values(&["copy", "symlink"])
+                        .possible_values(["copy", "symlink"])
                         .takes_value(true),
                 )
                 .arg(
@@ -174,7 +174,7 @@ fn main() -> Result<()> {
                             "Always skip post-installation setup checks. This can be set temporarily \
                              by passing the '--no-verify' option to 'yabridgectl sync'.",
                         )
-                        .possible_values(&["true", "false"])
+                        .possible_values(["true", "false"])
                         .takes_value(true),
                 ),
         )