buildPredicate not final anymore to allow for override in subclasses

This is the first step to finally make the DeckSetFilter working properly!
So far, the filter applies if **all** the cards in a deck matches selected specific set(s).
We will allow for customisation to simplify and correct this filter - more in the next commit.

forge-gui-desktop/src/main/java/forge/itemmanager/filters/DeckFormatFilter.java

@@ -25,7 +25,7 @@ public class DeckFormatFilter extends FormatFilter<DeckProxy> {
     }
 
     @Override
-    protected final Predicate<DeckProxy> buildPredicate() {
+    protected Predicate<DeckProxy> buildPredicate() {
         return DeckProxy.createPredicate(SFilterUtil.buildFormatFilter(this.formats, this.allowReprints));
     }