Fix bug where open graph and Twitter cards expect an image URL
Fix bug where open graph and Twitter cards expect an image URL

not a path (even though they figure it out ;)

ansonK/e-petitions,telekomatrix/e-petitions,alphagov/e-petitions,alphagov/e-petitions,unboxed/e-petitions,StatesOfJersey/e-petitions,StatesOfJersey/e-petitions,alphagov/e-petitions,unboxed/e-petitions,ansonK/e-petitions,joelanman/e-petitions,telekomatrix/e-petitions,joelanman/e-petitions,StatesOfJersey/e-petitions,unboxed/e-petitions,oskarpearson/e-petitions,telekomatrix/e-petitions,ansonK/e-petitions,oskarpearson/e-petitions,StatesOfJersey/e-petitions,joelanman/e-petitions,alphagov/e-petitions,oskarpearson/e-petitions,unboxed/e-petitions