Using config.beforeRedirect prevents using proxy on redirected requests

[mbargiel]

Describe the bug

The support for config.beforeRedirect introduced a regression of #3369 when both config.beforeRedirect and a proxy are used. Both of them internally set options.beforeRedirect. Moreover, config.beforeRedirect is not re-applied on subsequent redirections.

To Reproduce

Adding the following test in test/unit/adapters/http.js

  it('should support beforeRedirect and proxy with redirect', function (done) {
    var requestCount = 0;
    var totalRedirectCount = 5;
    server = http.createServer(function (req, res) {
      requestCount += 1;
      if (requestCount <= totalRedirectCount) {
        res.setHeader('Location', 'http://localhost:4444');
        res.writeHead(302);
      }
      res.end();
    }).listen(4444, function () {
      var proxyUseCount = 0;
      proxy = http.createServer(function (request, response) {
        proxyUseCount += 1;
        var parsed = url.parse(request.url);
        var opts = {
          host: parsed.hostname,
          port: parsed.port,
          path: parsed.path
        };

        http.get(opts, function (res) {
          response.writeHead(res.statusCode, res.headers);
          res.on('data', function (data) {
            response.write(data)
          });
          res.on('end', function () {
            response.end();
          });
        });
      }).listen(4000, function () {
        var configBeforeRedirectCount = 0;
        axios.get('http://localhost:4444/', {
          proxy: {
            host: 'localhost',
            port: 4000
          },
          maxRedirects: totalRedirectCount,
          beforeRedirect: function (options) {
            configBeforeRedirectCount += 1;
          }
        }).then(function (res) {
          assert.equal(totalRedirectCount, configBeforeRedirectCount, 'should invoke config.beforeRedirect option on every redirect');
          assert.equal(totalRedirectCount + 1, proxyUseCount, 'should go through proxy on every redirect');
          done();
        }).catch(done);
      });
    });
  });

Expected behavior

The test should pass, but currently 'should go through proxy on every redirect' assertion fails.

Environment

• Axios Version 0.27.2
• Adapter HTTP
• Browser N/A
• Browser Version N/A
• Node.js Version N/A
• OS: N/A
• Additional Library Versions N/A

Additional context/Screenshots

I'm working on a small PR to fix this issue.