Fix err condition

lib/policies/systemErrorRetryPolicy.ts

@@ -121,7 +121,7 @@ function retry(policy: SystemErrorRetryPolicy, request: WebResource, operationRe
         .then(res => retry(policy, request, res, retryData, err))
         .catch(err => retry(policy, request, operationResponse, retryData, err));
   } else {
-    if (err == undefined) {
+    if (err != undefined) {
       // If the operation failed in the end, return all errors instead of just the last one
       err = retryData.error;
       return Promise.reject(err);