restore bookSource fix

app/src/main/java/io/legado/app/help/storage/ImportOldData.kt

@@ -92,7 +92,7 @@ object ImportOldData {
         return books.size
     }
 
-    private fun importOldSource(json: String): Int {
+    fun importOldSource(json: String): Int {
         val bookSources = mutableListOf<BookSource>()
         val items: List<Map<String, Any>> = Restore.jsonPath.parse(json).read("$")
         for (item in items) {

app/src/main/java/io/legado/app/help/storage/Restore.kt

@@ -125,6 +125,10 @@ object Restore {
             }
             fileToListT<BookSource>(path, "bookSource.json")?.let {
                 appDb.bookSourceDao.insert(*it.toTypedArray())
+            } ?: run {
+                val bookSourceFile = FileUtils.createFileIfNotExist(path + File.separator + "bookSource.json")
+                val json = bookSourceFile.readText()
+                ImportOldData.importOldSource(json)
             }
             fileToListT<RssSource>(path, "rssSources.json")?.let {
                 appDb.rssSourceDao.insert(*it.toTypedArray())