fix(library): Sort by latest chapter is not working properly

`last_update` is now when entry chapter list is changed instead of when is
the latest entry uploaded. It is now replaced by LibraryManga's
latestUpdate

Fixes GH-309

CHANGELOG.md

@@ -9,10 +9,14 @@ The format is simplified version of [Keep a Changelog](https://keepachangelog.co
 - `Translation` - Translation changes/updates
 - `Other` - Technical changes/updates
 
+## [Unreleased]
+
+### Fixes
+- Fix sorting by latest chapter is not working properly
+
 ## [1.9.6]
 
 ### Fixes
-- Fix weird flickering when browsing sources
 - Fix some crashes
 
 ## [1.9.5]

app/src/main/java/eu/kanade/tachiyomi/ui/library/LibraryPresenter.kt

@@ -658,7 +658,7 @@ class LibraryPresenter(
                     category.mangaSort != null -> {
                         var sort = when (category.sortingMode() ?: LibrarySort.Title) {
                             LibrarySort.Title -> sortAlphabetical(i1, i2)
-                            LibrarySort.LatestChapter -> i2.manga.last_update.compareTo(i1.manga.last_update)
+                            LibrarySort.LatestChapter -> i2.manga.latestUpdate.compareTo(i1.manga.latestUpdate)
                             LibrarySort.Unread -> when {
                                 i1.manga.unread == i2.manga.unread -> 0
                                 i1.manga.unread == 0 -> if (category.isAscending()) 1 else -1