usync-ping reports failure when it connects on the last attempt #20

usync-ping reports failure if it connects on its last attempt.

On success the loop breaks with count still at its current value, and the check afterwards can't tell that apart from running out of retries:

https://github.com/Jumoo/uSync.CommandLine/blob/de15939/uSync.Commands/uSync/uSyncPingCommand.cs#L43-L66

To reproduce

Run this against a healthy site, using uSync.Cli 17.0.0:

uSyncCli usync-ping --retrys 1

It prints Failed to ping server and exits with 1. With --retrys 3 against the same site, it connects first time and exits with 0.

The same thing happens with the default of 10 retries if the server first responds on the tenth attempt, which is the case a script waiting for a site to boot cares about.

Fix

Set a connected flag when AttemptConnection succeeds, and use it for both the message and the exit code instead of comparing count to retries.