优化

app/src/main/java/io/legado/app/ui/main/MainActivity.kt

@@ -99,6 +99,7 @@ class MainActivity : VMBaseActivity<ActivityMainBinding, MainViewModel>(),
             val lastBackupFile = withContext(IO) { AppWebDav.lastBackUp().getOrNull() }
                 ?: return@launch
             if (lastBackupFile.lastModify - LocalConfig.lastBackup > DateUtils.MINUTE_IN_MILLIS) {
+                LocalConfig.lastBackup = lastBackupFile.lastModify
                 alert("恢复", "webDav书源比本地新,是否恢复") {
                     cancelButton()
                     okButton {