Fixed "no custom seals -> crash" bug.

src/main/java/forge/control/home/ControlSealed.java

@@ -184,6 +184,7 @@ public class ControlSealed {
                     + ">> does not equal any of the sealedTypes.");
         }
 
+        if (!sd.getCardpool().isEmpty()) {
             final ItemPool<CardPrinted> sDeck = sd.getCardpool();
 
             deck.getSideboard().addAll(sDeck);
@@ -217,6 +218,7 @@ public class ControlSealed {
                 view.getParentView().getUtilitiesController().showDeckEditor(GameType.Sealed, deck);
             }
         }
+    }
 
     /** @return {@link forge.Command} What to do when the deck editor exits. */
     public Command getExitCommand() {