THRIFT-834. csharp: THttpClient resends contents of message after transport errors

This patch causes the send buffer to be refreshed even in the case of errors.

Patch: Anatoly Fayngelerin

git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@983067 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/csharp/src/Transport/THttpClient.cs b/lib/csharp/src/Transport/THttpClient.cs
index d5d4abc..bf6ca4d 100644
--- a/lib/csharp/src/Transport/THttpClient.cs
+++ b/lib/csharp/src/Transport/THttpClient.cs
@@ -121,8 +121,14 @@
 
 		public override void Flush()
 		{
-			SendRequest();
-			outputStream = new MemoryStream();
+			try 
+			{
+				SendRequest();
+			}
+			finally
+			{
+				outputStream = new MemoryStream();
+			}
 		}
 
 		private void SendRequest()