When it is NotActive no need to log error (#1631)

Author: vicancy

src/Microsoft.Azure.SignalR/ServerConnections/ServiceConnection.cs

@@ -9,6 +9,7 @@
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Connections;
 using Microsoft.AspNetCore.Http;
+using Microsoft.Azure.SignalR.Common;
 using Microsoft.Azure.SignalR.Protocol;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Primitives;
@@ -337,6 +338,11 @@ private async Task ProcessOutgoingMessagesAsync(ClientConnectionContext connecti
                             // Forward the message to the service
                             await WriteAsync(new ConnectionDataMessage(connection.ConnectionId, buffer));
                         }
+                        catch (ServiceConnectionNotActiveException)
+                        {
+                            // Service connection not active means the transport layer for this connection is closed, no need to continue processing
+                            break;
+                        }
                         catch (Exception ex)
                         {
                             Log.ErrorSendingMessage(Logger, ex);