message: fix(umi): correct export for http-proxy-middleware
diff: import express from '@umijs/bundler-utils/compiled/express';
  -import httpProxyMiddleware from '@umijs/bundler-webpack/compiled/http-proxy-middleware';
  +import * as httpProxyMiddleware from '@umijs/bundler-webpack/compiled/http-proxy-middleware';
  export * from '@umijs/utils';
  export { httpProxyMiddleware, express };
  