THRIFT-4609 keep InnerException wherever appropriate
Client: C#
Patch: Jens Geyer

This closes #1576
diff --git a/lib/csharp/src/Transport/TTLSServerSocket.cs b/lib/csharp/src/Transport/TTLSServerSocket.cs
index aa8ff7c..716a97c 100644
--- a/lib/csharp/src/Transport/TTLSServerSocket.cs
+++ b/lib/csharp/src/Transport/TTLSServerSocket.cs
@@ -129,10 +129,10 @@
                 this.server = TSocketVersionizer.CreateTcpListener(this.port);
                 this.server.Server.NoDelay = true;
             }
-            catch (Exception)
+            catch (Exception ex)
             {
                 server = null;
-                throw new TTransportException("Could not create ServerSocket on port " + this.port + ".");
+                throw new TTransportException("Could not create ServerSocket on port " + this.port + ".", ex);
             }
         }
 
@@ -150,7 +150,7 @@
                 }
                 catch (SocketException sx)
                 {
-                    throw new TTransportException("Could not accept on listening socket: " + sx.Message);
+                    throw new TTransportException("Could not accept on listening socket: " + sx.Message, sx);
                 }
             }
         }
@@ -197,7 +197,7 @@
             }
             catch (Exception ex)
             {
-                throw new TTransportException(ex.ToString());
+                throw new TTransportException(ex.ToString(), ex);
             }
         }
 
@@ -214,7 +214,7 @@
                 }
                 catch (Exception ex)
                 {
-                    throw new TTransportException("WARNING: Could not close server socket: " + ex);
+                    throw new TTransportException("WARNING: Could not close server socket: " + ex, ex);
                 }
                 this.server = null;
             }