Fix flaky test.

test/Common/ContainerHostTests.cs

@@ -142,6 +142,7 @@ namespace Test.Amqp
             var connection = new Connection(Address);
             var session = new Session(connection);
             var receiver = new ReceiverLink(session, "receiver0", name);
+            receiver.SetCredit(count, CreditMode.Manual);
             int released = 0;
             int rejected = 0;
             int ignored = 0;