If I start a profile with DS enabled but no internet connection we throw some unexpected errors

Failed to fetch https://getpocket.cdn.mozilla.net/v3/firefox/global-recs?topic_id=1&duration=2592000&end_time_offset=172800&version=3&consumer_key=40249-e88c401e1b1f2242d9e441c4&locale_lang=en-US&feed_variant=OptimalCuratedLinksForLocaleFeed&model_id=external_time_live: NetworkError when attempting to fetch resource. DiscoveryStreamFeed.jsm:124
No response for feed DiscoveryStreamFeed.jsm:564
Error trying to load component feed https://getpocket.cdn.mozilla.net/v3/firefox/global-recs?topic_id=1&duration=2592000&end_time_offset=172800&version=3&consumer_key=$apiKey&locale_lang=en-US&feed_variant=OptimalCuratedLinksForLocaleFeed&model_id=external_time_live: TypeError: feed is null DiscoveryStreamFeed.jsm:259
Error trying to load component feeds: TypeError: newFeeds[currentValue] is null DiscoveryStreamFeed.jsm:606

And if I then enable the internet connection we don't do a retry but wait for the next system tick.
Also attached in the screenshot if the feed is loaded but then I lose connectivity the images show a "broken loaded state".

topstories used css background-image while the discoverystream uses <picture>/<img> (resulting in the error icon) so might need to add an onerror handler here

https://hg.mozilla.org/mozilla-central/rev/5c4931404035

I have verified that this issue is no longer reproducible with the latest Firefox Nightly (68.0a1 Build ID - 20190506214617) installed, on Windows 10 x64, Arch Linux and Mac 10.13.3. Now, the "broken loaded state" is no longer displayed on the images anymore.