fix: NetworkManager.ShutdownInProgress not being reset#2661

SamuelBellomo merged 4 commits intorelease/1.6.0Unity-Technologies/com.unity.netcode.gameobjects:release/1.6.0from

fix/networkmanager-shuttingdown-not-being-resetUnity-Technologies/com.unity.netcode.gameobjects:fix/networkmanager-shuttingdown-not-being-resetCopy head branch name to clipboard