weixin账号抓取方法，增加category_list作为输入

coldStartTasks/crawler/weixinAccountCrawler.py

@@ -14,7 +14,7 @@ class weixinAccountCrawler(object):
     """
 
     def __init__(self, target_url_list):
-        self.db_client = longArticlesMySQL
+        self.db_client = longArticlesMySQL()
         self.spider = WeixinSpider()
         self.url_list = target_url_list