Add magazine auto-eject message back in (#1191)

I goofed.

Co-authored-by: Metal Gear Sloth <metalgearsloth@gmail.com>

Content.Shared/GameObjects/Components/Weapons/Ranged/MagazineAutoEjectMessage.cs

@@ -0,0 +1,12 @@
+using System;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Serialization;
+
+namespace Content.Shared.GameObjects.Components.Weapons.Ranged
+{
+    /// <summary>
+    /// This is sent if the MagazineBarrel AutoEjects the magazine
+    /// </summary>
+    [Serializable, NetSerializable]
+    public sealed class MagazineAutoEjectMessage : ComponentMessage {}
+}