Reset sort on update if using old sort by source setting

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

@@ -8,4 +8,7 @@ object LibrarySort {
     const val UNREAD = 3
     const val TOTAL = 4
     const val LATEST_CHAPTER = 6
+
+    @Deprecated("Removed in favor of searching by source")
+    const val SOURCE = 5
 }