[BUGFIX] Add check for if Instagram entries have media_url set

[sturmundbraem]

@MattiasNilsson Thanks for the fix! Do I understand correctly that this will just skip the post? Does the insta API allow to poll deeper into the CAROUSEL_ALBUM's elements if media_url is missing or isn't that possible?

[MattiasNilsson]

@sturmundbraem It will skip the post and it is not possible to traverse the CAROUSEL_ALBUM.

[sturmundbraem]

Thanks @MattiasNilsson !