message: Fix bootstrap starting of Lean (the clientProvider had a bad cached entry for the LeanClient that failed to start).
diff: @@ -237,7 +237,13 @@ export class LeanClientProvider implements Disposable {
  return [false, undefined];
  }
  - client.serverFailed((err) => window.showErrorMessage(err));
  + client.serverFailed((err) => {
  + // forget this client!
  + const cached = this.clients.get(path);
  + this.clients.delete(path);
  + cached?.dispose();
  + window.showErrorMessage(err);
  + });
  // aggregate progress changed events.
  client.progressChanged(arg => {
  