Use direct executor in client

src/main/java/it/cavallium/rockserver/core/client/GrpcConnection.java

@@ -65,6 +65,7 @@ public class GrpcConnection extends BaseConnection implements RocksDBAPI {
 		super(name);
 		var channelBuilder = ManagedChannelBuilder
 				.forAddress(address.host(), address.port())
+				.directExecutor()
 				.usePlaintext();
 		this.channel = channelBuilder.build();
 		this.blockingStub = RocksDBServiceGrpc.newBlockingStub(channel);

src/main/java/it/cavallium/rockserver/core/server/GrpcServer.java

@@ -772,6 +772,8 @@ public class GrpcServer extends Server {
 			if (ex instanceof CompletionException exx) {
 				handleError(responseObserver, exx.getCause());
 			} else {
+				var serverResponseObserver = ((ServerCallStreamObserver<?>) responseObserver);
+				if (!serverResponseObserver.isCancelled()) {
 					if (ex instanceof RocksDBException e) {
 						responseObserver.onError(Status.INTERNAL
 								.withDescription(e.getLocalizedMessage())
@@ -782,6 +784,9 @@ public class GrpcServer extends Server {
 								.withCause(ex)
 								.asException());
 					}
+				} else {
+					LOG.error("Unexpected error", ex);
+				}
 			}
 		}
 	}