fix: 抖音/TikTok 未填标签时 self.tags=None 导致 len() 崩溃，兜底为 []

uploader/douyin_uploader/main.py

@@ -653,7 +653,7 @@ class DouYinVideo(DouYinBaseUploader):
         )
         self.title = title
         self.file_path = file_path
-        self.tags = tags
+        self.tags = tags or []
         self.thumbnail_landscape_path = thumbnail_landscape_path
         self.thumbnail_portrait_path = thumbnail_portrait_path
         self.productLink = productLink

uploader/tk_uploader/main.py

@@ -73,7 +73,7 @@ class TiktokVideo(object):
     def __init__(self, title, file_path, tags, publish_date, account_file):
         self.title = title
         self.file_path = file_path
-        self.tags = tags
+        self.tags = tags or []
         self.publish_date = publish_date
         self.account_file = account_file
         self.headless = LOCAL_CHROME_HEADLESS

uploader/tk_uploader/main_chrome.py

@@ -75,7 +75,7 @@ class TiktokVideo(object):
     def __init__(self, title, file_path, tags, publish_date, account_file, thumbnail_path=None):
         self.title = title
         self.file_path = file_path
-        self.tags = tags
+        self.tags = tags or []
         self.publish_date = publish_date
         self.thumbnail_path = thumbnail_path
         self.account_file = account_file