Time: Run synchronization on network up.

Also move the settings check into launch_daemon, as that way
"Time --update" can be invoked even when the setting is disabled.

Fixes #9348.

data/launch/user

@@ -37,6 +37,8 @@ target desktop {
 
 	job update-time {
 		launch /system/preferences/Time "" --update
+		if setting ~/config/settings/networktime\ settings "synchronize at boot"
+		on network_available
 	}
 
 	job first-login {

src/preferences/time/Time.cpp

@@ -91,9 +91,6 @@ main(int argc, char** argv)
 			return 0;
 
 		Settings settings;
-		if (!settings.GetSynchronizeAtBoot())
-			return 0;
-
 		const char* errorString = NULL;
 		int32 errorCode = 0;
 		if (update_time(settings, &errorString, &errorCode) == B_OK) {