Made SteamGame immune to apps with no image
Made SteamGame immune to apps with no image

Fixes koraktor/steam-condenser#167

bfosberry/steam-condenser-ruby,hcool/steam-condenser-ruby,kickback/steam-condenser-ruby,koraktor/steam-condenser-ruby,Arie/steam-condenser-ruby,jpalumickas/steam-condenser-ruby