feat: 优化代码

app/src/main/java/io/legado/app/ui/book/info/BookInfoViewModel.kt

@@ -133,6 +133,7 @@ class BookInfoViewModel(application: Application) : BaseViewModel(application) {
         execute {
             if (inBookshelf) {
                 bookData.value?.let {
+                    book.group = it.group
                     book.order = it.order
                     App.db.bookDao().delete(it)
                 }

app/src/main/java/io/legado/app/ui/book/read/ReadBookViewModel.kt

@@ -136,6 +136,7 @@ class ReadBookViewModel(application: Application) : BaseViewModel(application) {
         execute {
             ReadBook.upMsg(null)
             ReadBook.book?.let {
+                book1.group = it.group
                 book1.order = it.order
                 App.db.bookDao().delete(it)
             }