Change uname to kernel commit, Fix CI build

src/scheme/sys/uname.rs

@@ -6,7 +6,7 @@ pub fn resource(_token: &mut CleanLockToken) -> Result<Vec<u8>> {
         "Redox\n{}\n{}\n{}\n",
         env!("CARGO_PKG_VERSION"),
         env!("TARGET").split('-').next().unwrap(),
-        env!("COOKBOOK_COMMIT_IDENT")
+        option_env!("COOKBOOK_SOURCE_IDENT").unwrap_or("")
     )
     .into_bytes())
 }