Fix "is read" detection in single/double page mode

In case the last page of a manga was immediately visible or the became visible after the "image spread state" change, the chapter never got marked as read

src/modules/reader/components/viewer/ReaderViewer.tsx

@@ -138,6 +138,7 @@ export const ReaderViewer = forwardRef((_, ref: ForwardedRef<HTMLDivElement | nu
 
         const convertPagesToDoublePageMode = readingMode.value === ReadingMode.DOUBLE_PAGE;
         if (convertPagesToDoublePageMode) {
+            updateCurrentPageIndex(getNextIndexFromPage(getPage(currentPageIndex, actualPages)));
             setPages(actualPages);
             setWasDoublePageMode(readingMode.value === ReadingMode.DOUBLE_PAGE);
         }