Obtain network state from GNetworkMonitor The PackageKit daemon does not necessarily run continuously and is therefore not a reliable source for network changes. More specifically, if the internet connectivity is not available when the PackageKit daemon shuts down, package-update-indicator will not be notified if connectivity is restored. Thus use GNetworkMonitor instead which is also used internally by PackageKit. This change is based on patches by Cliff <cliffd@gmx.com.br> who discovered and tracked down this issue.