message: updated let to const for constant variable
diff: @@ -141,7 +141,7 @@ export class SubstituteCommand extends node.CommandBase {
  matchIndex: number
  ): Promise<boolean> {
  const cancellationToken = new vscode.CancellationTokenSource();
  - let validSelections: string[] = ['y', 'n', 'a', 'q', 'l'];
  + const validSelections: string[] = ['y', 'n', 'a', 'q', 'l'];
  let selection: string = '';
  const searchRanges: vscode.Range[] = [
  