macosx: Do not display unnecessary disc number strings when there is no real disc number

Signed-off-by: Claudio Cambra <developer@claudiocambra.com>

modules/gui/macosx/library/VLCLibraryCollectionViewMediaItemSupplementaryDetailView.m

@@ -94,7 +94,7 @@ NSCollectionViewSupplementaryElementKind const VLCLibraryCollectionViewMediaItem
 
     VLCInputItem * const inputItem = actualItem.inputItem;
     NSString * const discNumber = inputItem.discNumber;
-    if (![discNumber isEqualToString:@""]) {
+    if (![discNumber isEqualToString:@""] && ![discNumber isEqualToString:@"0"]) {
         [strings addObject:[NSString stringWithFormat:@"%@ %@", _NS("Disc"), discNumber]];
     }