feat: add string and fix bug

app/src/main/java/io/legado/app/model/ReadBook.kt

@@ -49,6 +49,7 @@ object ReadBook : CoroutineScope by MainScope() {
 
     //暂时保存跳转前进度
     fun saveCurrentBookProcess() {
+        if (lastBookPress != null) return //避免进度条连续跳转不能覆盖最初的进度记录
         lastBookPress = book?.let { BookProgress(it) }
     }
     //恢复跳转前进度

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

@@ -996,6 +996,7 @@ class ReadBookActivity : BaseReadBookActivity(),
 
     /* 恢复到 全文搜索/进度条跳转前的位置 */
     private fun restoreLastBookProcess() {
+        // 默认提示恢复
         alert(R.string.draw) {
             setMessage(R.string.restore_last_book_process)
             yesButton {