Fix file duplication

Increase icon size for scan library icon

lector/threaded.py

@@ -58,7 +58,11 @@ class BackGroundBookAddition(QtCore.QThread):
             self.database_path,
             self.parent.settings['auto_tags'],
             self.parent.temp_dir.path())
+
         parsed_books = books.initiate_threads()
+        if not parsed_books:
+            return
+
         self.parent.lib_ref.generate_model('addition', parsed_books, False)
         if self.prune_required:
             self.parent.lib_ref.prune_models(self.file_list)