refactor($http): drop superfluous argument to sendReq

src/ng/http.js

@@ -771,7 +771,7 @@ function $HttpProvider() {
         }
 
         // send request
-        return sendReq(config, reqData, headers).then(transformResponse, transformResponse);
+        return sendReq(config, reqData).then(transformResponse, transformResponse);
       };
 
       var chain = [serverRequest, undefined];
@@ -1004,11 +1004,12 @@ function $HttpProvider() {
      * !!! ACCESSES CLOSURE VARS:
      * $httpBackend, defaults, $log, $rootScope, defaultCache, $http.pendingRequests
      */
-    function sendReq(config, reqData, reqHeaders) {
+    function sendReq(config, reqData) {
       var deferred = $q.defer(),
           promise = deferred.promise,
           cache,
           cachedResp,
+          reqHeaders = config.headers,
           url = buildUrl(config.url, config.params);
 
       $http.pendingRequests.push(config);