better exception messages

Author: honfika

src/Titanium.Web.Proxy/Helpers/HttpServerStream.cs

@@ -39,15 +39,15 @@ internal async ValueTask<ResponseStatusInfo> ReadResponseStatus(CancellationToke
                 {
                     // is this really possible?
                     httpStatus = await ReadLineAsync(cancellationToken) ??
-                                 throw new ServerConnectionException("Server connection was closed.");
+                                 throw new ServerConnectionException("Server connection was closed. Response status is empty.");
                 }
 
                 Response.ParseResponseLine(httpStatus, out var version, out int statusCode, out string description);
                 return new ResponseStatusInfo { Version = version, StatusCode = statusCode, Description = description };
             }
             catch (Exception e) when (!(e is ServerConnectionException))
             {
-                throw new ServerConnectionException("Server connection was closed.");
+                throw new ServerConnectionException("Server connection was closed. Exception while reading the response status.", e);
             }
         }
     }