beeminder: Remove duplicated try-except in initialize method.

Remove duplicated try-except in `initialize` method because
ConnectionError is already catched in `get_beeminder_response` method.

zulip_bots/zulip_bots/bots/beeminder/beeminder.py

@@ -83,13 +83,9 @@ class BeeminderHandler(object):
     def initialize(self, bot_handler: Any) -> None:
         self.config_info = bot_handler.get_config_info('beeminder')
         # Check for valid auth_token
-        try:
         result = get_beeminder_response('5', self.config_info)
         if result == "Error. Check your key!":
             bot_handler.quit('Invalid key!')
-        except ConnectionError:
-            logging.warning('Bad connection')
-            raise
 
     def usage(self) -> str:
         return "This plugin allows users to add datapoints towards their Beeminder goals"