THRIFT-4831 interface ITProtocolFactory should be class TProtocolFactory again
Client: netstd
Patch: Jens Geyer

This closes #1767
diff --git a/lib/netstd/Thrift/Protocol/TJSONProtocol.cs b/lib/netstd/Thrift/Protocol/TJSONProtocol.cs
index fab1385..8e40c48 100644
--- a/lib/netstd/Thrift/Protocol/TJSONProtocol.cs
+++ b/lib/netstd/Thrift/Protocol/TJSONProtocol.cs
@@ -785,9 +785,9 @@
         /// <summary>
         ///     Factory for JSON protocol objects
         /// </summary>
-        public class Factory : ITProtocolFactory
+        public class Factory : TProtocolFactory
         {
-            public TProtocol GetProtocol(TTransport trans)
+            public override TProtocol GetProtocol(TTransport trans)
             {
                 return new TJsonProtocol(trans);
             }