Replace non-existent prototype in ToolLockerFillComponent (#341)

Previously this component would sometimes try to use a non-existent prototype, `HelmetEngineering`. This would result in a server crash upon loading any map that uses the `Tool Locker (Filled)` component. This replaces that non existent prototype with `HatHardhatRed`, which does exist, and is something you might expect to find in a tool locker.

Content.Server/GameObjects/Components/Items/Storage/Fill/ToolLockerFillComponent.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using Robust.Server.Interfaces.GameObjects;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Interfaces.GameObjects;
@@ -80,7 +80,7 @@ namespace Content.Server.GameObjects.Components.Items.Storage.Fill
 
             if (random.Prob(0.4f))
             {
-                Spawn("HelmetEngineering");
+                Spawn("HatHardhatRed");
             }
 
             for (var i = 0; i < 3; i++)