Subscription drop handling broken in 22.0.0

[alexeyzimarev]

Describe the bug
When the subscription drops, the latest client gets stuck in an exception loop, which prevents the application from doing anything like restoring the subscription.

To Reproduce
Steps to reproduce the behavior:

1. Described in details in the repro https://github.com/alexeyzimarev/EsdbSubscriptionDrop

Expected behavior
When the subscription drops, the Dropped delegate is called, then the subscription stops working

Actual behavior
The client keeps produces the following exception endlessly:

[15:46:29 ERR] Error starting gRPC call. <s:Grpc.Net.Client.Internal.GrpcCall>;
System.Net.Http.HttpRequestException: Connection refused (localhost:2113)
 ---> System.Net.Sockets.SocketException (61): Connection refused
   at System.Net.Sockets.Socket.AwaitableSocketAsyncEventArgs.System.Threading.Tasks.Sources.IValueTaskSource.GetResult(Int16 token)
   at System.Net.Sockets.Socket.<ConnectAsync>g__WaitForConnectWithCancellation|277_0(AwaitableSocketAsyncEventArgs saea, ValueTask connectTask, CancellationToken cancellationToken)
   at System.Net.Http.HttpConnectionPool.ConnectToTcpHostAsync(String host, Int32 port, HttpRequestMessage initialRequest, Boolean async, CancellationToken cancellationToken)
   --- End of inner exception stack trace ---
   at System.Net.Http.HttpConnectionPool.ConnectToTcpHostAsync(String host, Int32 port, HttpRequestMessage initialRequest, Boolean async, CancellationToken cancellationToken)
   at System.Net.Http.HttpConnectionPool.ConnectAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
   at System.Net.Http.HttpConnectionPool.AddHttp2ConnectionAsync(HttpRequestMessage request)
   at System.Threading.Tasks.TaskCompletionSourceWithCancellation`1.WaitWithCancellationAsync(CancellationToken cancellationToken)
   at System.Net.Http.HttpConnectionPool.GetHttp2ConnectionAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
   at System.Net.Http.HttpConnectionPool.SendWithVersionDetectionAndRetryAsync(HttpRequestMessage request, Boolean async, Boolean doRequestAuth, CancellationToken cancellationToken)
   at System.Net.Http.DiagnosticsHandler.SendAsyncCore(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
   at System.Net.Http.RedirectHandler.SendAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
   at System.Net.Http.HttpClient.<SendAsync>g__Core|83_0(HttpRequestMessage request, HttpCompletionOption completionOption, CancellationTokenSource cts, Boolean disposeCts, CancellationTokenSource pendingRequestsCts, CancellationToken originalCancellationToken)
   at Grpc.Net.Client.Internal.GrpcCall`2.GetResponseHeadersCoreAsync()

Environment details are in the repro repository.

[alexeyzimarev]

Actually, resubscribe works. It's just I haven't seen my own issue between those millions of log messages.