THRIFT-4772 fully enable server-side usage of framed/buffered transports
Client: netstd
Patch: Jens Geyer

This closes #1729
diff --git a/lib/netstd/Thrift/Server/TServer.cs b/lib/netstd/Thrift/Server/TServer.cs
index 3a70c07..b351913 100644
--- a/lib/netstd/Thrift/Server/TServer.cs
+++ b/lib/netstd/Thrift/Server/TServer.cs
@@ -45,8 +45,8 @@
         {
             ProcessorFactory = processorFactory ?? throw new ArgumentNullException(nameof(processorFactory));
             ServerTransport = serverTransport;
-            InputTransportFactory = inputTransportFactory ?? throw new ArgumentNullException(nameof(inputTransportFactory));
-            OutputTransportFactory = outputTransportFactory ?? throw new ArgumentNullException(nameof(outputTransportFactory));
+            InputTransportFactory = inputTransportFactory ?? new TTransportFactory();
+            OutputTransportFactory = outputTransportFactory ?? new TTransportFactory();
             InputProtocolFactory = inputProtocolFactory ?? throw new ArgumentNullException(nameof(inputProtocolFactory));
             OutputProtocolFactory = outputProtocolFactory ?? throw new ArgumentNullException(nameof(outputProtocolFactory));
             Logger = logger; // null is absolutely legal
@@ -84,4 +84,4 @@
             }
         }
     }
-}
\ No newline at end of file
+}