twitter: /statuses/retweets.json returns 403 Forbidden

[snarfed]

for https://brid.gy/twitter/iwontsignuphere , every poll. other API calls beforehand succeed. not sure why. we're incorrectly (maybe?) interpreting it as rate limiting.

example log:

Params: NestedMultiDict([('last_polled', u'1970-01-01-00-00-00'), ('source_key', u'aglzfmJy...')])
Source: iwontsignuphere (Twitter) iwontsignuphere, http://brid.gy/twitter/iwontsignuphere
Last poll: http://brid.gy/log?start_time=1469094672&key=aglzfmJyaWQtZ3lyHAsSB1R3aXR0ZXIiD2l3b250c2lnbnVwaGVyZQw
Updating iwontsignuphere (Twitter) /twitter/iwontsignuphere : {'poll_status': 'polling', 'last_poll_attempt': datetime.datetime(2016, 7, 21, 10, 52, 18, 474590)}
urlopen GET https://api.twitter.com/1.1/search/tweets.json?q=%22julieannenoying.com%22&include_entities=true&result_type=recent&count=50 {}
urlopen GET https://api.twitter.com/1.1/favorites/list.json?screen_name=&include_entities=true {}
urlopen GET https://api.twitter.com/1.1/account/verify_credentials.json {}
urlopen GET https://api.twitter.com/1.1/statuses/user_timeline.json?include_entities=true&count=50&screen_name= {}
urlopen GET https://api.twitter.com/1.1/statuses/retweets.json?id=744651175199383552 {}
Error 403, response body: {"errors":[{"code":"200", "message":"Forbidden."}]}
Error 403, response body: {"errors":[{"code":"200", "message":"Forbidden."}]}
Error 403, response body: {"errors":[{"code":"200", "message":"Forbidden."}]}
Error 403, response body: {"errors":[{"code":"200", "message":"Forbidden."}]}
Rate limited. Marking as error and finishing. HTTP Error 403: Forbidden
Updating iwontsignuphere (Twitter) /twitter/iwontsignuphere : {'poll_status': 'error', 'rate_limited': True}
Added poll task 62356658033700949421 with args {'countdown': 80642.525166884909}

[snarfed]

error code 200 isn't listed in https://dev.twitter.com/overview/api/response-codes , and https://dev.twitter.com/rest/reference/get/statuses/retweets/%3Aid doesn't mention this error.

however, https://twittercommunity.com/t/protected-tweets-with-statuses-retweets-id/12903/4 has lots of other people reporting the same thing: /statuses/retweets.json returns the same error for a protected account.

my best guess is this is intentional for protected accounts, so i should catch it and handle it.

[snarfed]

confirmed, same things happens with another protected account, snarfed_org: /statuses/retweets/701173347606880256.json returns 403 {"errors":[{"code":"200", "message":"Forbidden."}]}.

[snarfed]

fixed by snarfed/granary@34a7bcb