VkApi.captcha_handler: fix ignoring captcha

Author: python273

vk_api/vk_api.py

@@ -287,7 +287,7 @@ def check_token(self):
 
     def captcha_handler(self, captcha):
         """ http://vk.com/dev/captcha_error """
-        pass
+        raise captcha
 
     def need_validation_handler(self, error):
         """ http://vk.com/dev/need_validation """