Merge pull request #563 from AzureAD/oldaton/network_bg

Retry 500 error on background queue

Author: oldalton

IdentityCore/src/network/error_handler/MSIDAADRequestErrorHandler.m

@@ -53,9 +53,9 @@ - (void)handleError:(NSError * )error
 
         MSID_LOG_VERBOSE(context, @"Retrying network request, retryCounter: %ld", (long)httpRequest.retryCounter);
 
-        [httpRequest performSelector:@selector(sendWithBlock:)
-                          withObject:completionBlock
-                          afterDelay:(int64_t)httpRequest.retryInterval];
+        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(httpRequest.retryInterval * NSEC_PER_SEC)), dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
+            [httpRequest sendWithBlock:completionBlock];
+        });
 
         return;
     }