fix build and remove .cargo regs

.gitignore

@@ -30,6 +30,3 @@
 
 # Build artifacts
 out/
-
-# Cargo local dev config
-.cargo

parity/url.rs

@@ -46,12 +46,12 @@ pub fn open(url: &str) {
 	}
 }
 
-#[cfg(macos)]
+#[cfg(target_os="macos")]
 pub fn open(url: &str) {
 	let _ = std::process::Command::new("open").arg(url).output();
 }
 
-#[cfg(linux)]
+#[cfg(target_os="linux")]
 pub fn open(url: &str) {
 	let _ = std::process::Command::new("xdg-open").arg(url).output();
 }