Fix baseUrl and redirections.

[burningtree]

I found a bug in new baseUrl feature, when used in combination with redirection.

This script produce absurdly error [Error: options.uri must be a string when using options.baseUrl]:

var request = require('./node_modules/request');
var http = require('http');

var s = http.createServer(function(req, res) {
  if(req.url === '/redirect/') {
    res.writeHead(302, {
      location : '/'
    })
  } else  {
    res.statusCode = 200
  }
  res.end()
}).listen(6767);

request({
  url: '/',
  baseUrl: 'http://localhost:6767/redirect'

}, function (err, resp, body) {
  console.log(err);
  s.close();
});

This is due to the fact that first call changes URI to an object, and therefore in the second iteration (to redirected page) can be seen as a string. The solution is delete baseUrl immediately after use, because certainly no longer needed.

This pull request fixes this bug. Test included.

[simov]

Good catch @burningtree 👍