Update to LibHac 0.13.1 (#2475)

* Update to LibHac 0.13.1

* Recreate directories for indexed saves if they're missing on emulator start

Ryujinx.HLE/FileSystem/Content/ContentManager.cs

@@ -653,11 +653,11 @@ namespace Ryujinx.HLE.FileSystem.Content
 
         public SystemVersion VerifyFirmwarePackage(string firmwarePackage)
         {
-            _virtualFileSystem.Reload();
+            _virtualFileSystem.ReloadKeySet();
 
             // LibHac.NcaHeader's DecryptHeader doesn't check if HeaderKey is empty and throws InvalidDataException instead
             // So, we check it early for a better user experience.
-            if (_virtualFileSystem.KeySet.HeaderKey.IsEmpty())
+            if (_virtualFileSystem.KeySet.HeaderKey.IsZeros())
             {
                 throw new MissingKeyException("HeaderKey is empty. Cannot decrypt NCA headers.");
             }

Ryujinx.HLE/FileSystem/Content/SystemVersion.cs

@@ -1,4 +1,3 @@
-using System;
 using System.IO;
 using System.Text;