See https://ci.appveyor.com/project/Ladsgroup/pywikibot-g4xqx/build/1.0.208/job/lrlyi29b013fq0ar
```
>>> import pwb, pywikibot
>>> from pywikibot.comms.eventstreams import EventStreams
>>> stream = EventStreams(stream='recentchange')
>>> change = next(iter(stream))
Traceback (most recent call last):
File "<pyshell#6>", line 1, in <module>
change = next(iter(stream))
File "pywikibot\comms\eventstreams.py", line 265, in __iter__
self.source = EventSource(**self.sse_kwargs)
File "C:\Python27\lib\site-packages\sseclient.py", line 39, in __init__
self._connect()
File "C:\Python27\lib\site-packages\sseclient.py", line 52, in _connect
self.resp.raise_for_status()
File "C:\Python27\lib\site-packages\requests\models.py", line 840, in raise_for_status
raise HTTPError(http_error_msg, response=self)
HTTPError: 502 Server Error: Bad Gateway for url: https://stream.wikimedia.org/v2/stream/recentchange
>>>
```