NRE on /s when skins are loading

skins working great, I just noticed this when loading thousands of skins. It can take a while to complete and while it's in progress, if someone runs /s, it silently fails but logs

Failed executing chat command 's' in 'Skinner v3.0.5 by Whispers88' [callback] (Object reference not set to an instance of an object)
   at Dictionary<int, List<ulong>> Oxide.Plugins.Skinner.GetPlayerSkins(BasePlayer player, bool update) in /var/www/servers/christmas/carbon/plugins/Skinner.cs:line 2330
   at void Oxide.Plugins.Skinner+BoxController.StartAwake() in /var/www/servers/christmas/carbon/plugins/Skinner.cs:line 2998
   at void Oxide.Plugins.Skinner.SkinCMD(IPlayer iplayer, string command, string[] args) in /var/www/servers/christmas/carbon/plugins/Skinner.cs:line 1182
   at object System.Reflection.RuntimeMethodInfo.Invoke(object obj, BindingFlags invokeAttr, Binder binder, object[] parameters, CultureInfo culture)

It'd be cool if it could tell the player skins are currently loading or something similar. Otherwise works great.