Fix SealedCreatureAsset not properly saving the template

It saves it to the field but that field is overwritten by the return value, which was null, meaning it's effectively not being saved

ECCLibrary/ECCLibrary/Assets/SealedCreatureAsset.cs

@@ -37,7 +37,7 @@ public SealedCreatureAsset(PrefabInfo prefabInfo, CreatureTemplate template, Fun
     /// <returns></returns>
     protected override CreatureTemplate CreateTemplate()
     {
-        return null;
+        return Template;
     }
 
     /// <summary>