Ignore flakey Test from #1253 in CI

Author: mus65

test/Renci.SshNet.IntegrationTests/OldIntegrationTests/SftpClientTest.Upload.cs

@@ -77,6 +77,11 @@ public void Test_Sftp_Upload_Forbidden()
         [TestCategory("Sftp")]
         public void Test_Sftp_Multiple_Async_Upload_And_Download_10Files_5MB_Each()
         {
+            if (Environment.GetEnvironmentVariable("CI") == "true")
+            {
+                Assert.Inconclusive("Skipping because of failures in CI, see #1253");
+            }
+
             var maxFiles = 10;
             var maxSize = 5;