only add category if it exists
only add category if it exists

DallasMuseumArt/OctoberFriends,DallasMuseumArt/OctoberFriends,janusnic/OctoberFriends,DenverArtMuseum/OctoberFriends,janusnic/OctoberFriends,DallasMuseumArt/OctoberFriends,DenverArtMuseum/OctoberFriends,DenverArtMuseum/OctoberFriends,janusnic/OctoberFriends,artsmia/OctoberFriends,artsmia/OctoberFriends,artsmia/OctoberFriends