avoid errors when double clicking on a unit

the boongui_fullupdate_interval adds a small delay to what is displayed on the UI, if a unit has already died it will still be listed there till the next update, double clicking would cause an error.

gui/session/stats/BoonGUIStatsModesRowItem.js

@@ -32,7 +32,8 @@ class BoonGUIStatsModesRowItem {
 		if (move)
 		{
 			const entState = GetEntityState(entities[0]);
-			Engine.CameraMoveTo(entState.position.x, entState.position.z);
+			if (entState)
+				Engine.CameraMoveTo(entState.position.x, entState.position.z);
 		}
 	}