title: transformRequest not working in angularjs 1.2.21
body: <p>I am making api call method using $http.
  <br>
  I want to do some changes in request before service call.Hence, I am using <code>transformRequest</code> in config of $http.
  But this call is not working if I am using <code>transformRequest</code> or <code>transformResponse</code> in $http config.
  <br>
  Without <code>transformRequest</code> or <code>transformResponse</code> api call is working fine.</p>
  
  <pre><code>var deferred = $q.defer();
  $http({
          method: type,
          url: url,
          params: null,
          data: data,
          headers: null,
          transformRequest: function(data, headersGetter) {
              console.log('transformRequest');
          },
          transformResponse: function(data, headersGetter) {
              console.log('transformRequest');
          },
          cache: false,
          timeout: 120000 // 2 Min
      })
      .success(function(data, status, headers, config) {
          deferred.resolve(data);
      })
      .error(function(data, status, headers, config) {
          deferred.reject(data);
      });
  return deferred.promise;
  </code></pre>
  
  <p>My current version of angularjs is <strong>1.2.21</strong></p>