Don't crash if we try to refresh a non-host node, just skip it

renderdocui/Windows/Dialogs/RemoteManager.cs

@@ -179,6 +179,11 @@ namespace renderdocui.Windows.Dialogs
         {
             TreelistView.Node node = o as TreelistView.Node;
 
+            RemoteHost host = node.Tag as RemoteHost;
+
+            if(host == null)
+                return;
+
             Control p = node.OwnerView;
             while (p.Parent != null)
                 p = p.Parent;
@@ -189,8 +194,6 @@ namespace renderdocui.Windows.Dialogs
 
             string username = System.Security.Principal.WindowsIdentity.GetCurrent().Name;
 
-            RemoteHost host = node.Tag as RemoteHost;
-
             host.CheckStatus();
 
             SetRemoteServerLive(node, host.ServerRunning, host.Busy);