Prevent crash when removing cards from deck

forge-gui-mobile/src/forge/deck/FDeckEditor.java

@@ -447,17 +447,25 @@ public class FDeckEditor extends TabPageScreen<FDeckEditor> {
             });
         }
 
+        protected boolean canAddCards() {
+            return true;
+        }
+
         public void addCard(PaperCard card) {
+            if (canAddCards()) {
                 cardManager.addItem(card, 1);
                 parentScreen.getEditorType().getController().notifyModelChanged();
                 updateCaption();
             }
+        }
 
         public void addCards(Iterable<Entry<PaperCard, Integer>> cards) {
+            if (canAddCards()) {
                 cardManager.addItems(cards);
                 parentScreen.getEditorType().getController().notifyModelChanged();
                 updateCaption();
             }
+        }
 
         public void removeCard(PaperCard card) {
             cardManager.removeItem(card, 1);
@@ -495,8 +503,13 @@ public class FDeckEditor extends TabPageScreen<FDeckEditor> {
             refresh();
         }
 
+        @Override
+        protected boolean canAddCards() {
+            return false;
+        }
+
         protected String getItemManagerCaption() {
-            return "Catalog";
+            return "Cards";
         }
 
         @Override