adding account to s2s bidder-sync request (prebid#3123)

* adding account_id to s2s bidder-sync request

* changed param name from account_id to account

Author: harpere

modules/prebidServerBidAdapter/index.js

@@ -98,7 +98,8 @@ function queueSync(bidderCodes, gdprConsent) {
 
   const payload = {
     uuid: utils.generateUUID(),
-    bidders: bidderCodes
+    bidders: bidderCodes,
+    account: _s2sConfig.accountId
   };
 
   if (gdprConsent) {

test/spec/modules/prebidServerBidAdapter_spec.js

@@ -458,6 +458,8 @@ describe('S2S Adapter', function () {
 
         expect(requestBid.gdpr).is.equal(1);
         expect(requestBid.gdpr_consent).is.equal('abc123def');
+        expect(requestBid.bidders).to.contain('appnexus').and.to.have.lengthOf(1);
+        expect(requestBid.account).is.equal('1');
       });
 
       it('check gdpr info gets added into cookie_sync request: have consent data but gdprApplies is false', function () {