Fix autotests warning

idna/Cargo.toml

@@ -5,6 +5,7 @@ authors = ["The rust-url developers"]
 description = "IDNA (Internationalizing Domain Names in Applications) and Punycode."
 repository = "https://github.com/servo/rust-url/"
 license = "MIT/Apache-2.0"
+autotests = false
 
 [lib]
 doctest = false