CLI client may not exit upon some processing errors

[atomashpolskiy]

Because in CliClient.resume() we don't account for the case, when there is an exception in one of the async processing stages:

void resume() {
	...
	try {
		client.startAsync(state -> {
			printer.ifPresent(p -> p.print(state));
			if (!options.shouldSeedAfterDownloaded() && state.getPiecesRemaining() == 0) {
				runtime.shutdown();
			}
		}, 1000); // <-- CompletableFuture.whenComplete(it, ex) callback is needed here
	} catch (Throwable e) {
		// in case the start request to the tracker fails <-- this comment seems outdated
		printer.ifPresent(SessionStatePrinter::shutdown);
		printAndShutdown(e);
	}
}