message: fix(preset-umi): devTool dist not found
diff: @@ -2,7 +2,7 @@ import { existsSync } from 'fs';
  import { join } from 'path';
  import { IApi } from '../../types';
  -const devToolAppDist = join(__dirname, '../../../devToolApp/dist');
  +const devToolAppDist = join(__dirname, '../../../devToolAppDist');
  export default (api: IApi) => {
  api.addBeforeMiddlewares(() => {
  @@ -25,7 +25,7 @@ export default (api: IApi) => {
  // static
  if (path.startsWith('/__umi/')) {
  const shortPath = path.replace('/__umi/', '');
  - if (existsSync(join(devToolAppDist, shortPath))) {
  + if (shortPath !== '' && existsSync(join(devToolAppDist, shortPath))) {
  return res.sendFile(join(devToolAppDist, shortPath));
  } else {
  return res.sendFile(join(devToolAppDist, 'index.html'));
  