message: fix: code review remove dead code.
diff: @@ -347,12 +347,8 @@ export class LeanInstaller implements Disposable {
  const filterVersion = /version (\d+)\.\d+\..+/
  const match = filterVersion.exec(stdout)
  if (!match) {
  - if (!stdout) {
  - return { version: '', error: `lean4: '${cmd}' program not found.` }
  - } else {
  return { version: '', error: `lean4: '${cmd} ${options}' returned incorrect version string '${stdout}'.` }
  }
  - }
  const major = match[1];
  result.version = major
  }
  