api_service: Only fill in image info if we have it
api_service: Only fill in image info if we have it

Fixes #2738

s-urbaniak/rkt,ybubnov/rkt,lucasallan/rkt,jakon89/rkt,mike1729/rkt,kinvolk/rkt,lucasallan/rkt,yifan-gu/rocket,tmrts/rkt,tmrts/rkt,coreos/rkt,rkt/rkt,alban/rkt,euank/rkt,achanda/rkt,euank/rkt,yifan-gu/rkt,lucasallan/rkt,cab105/rkt,Shashwatsh/rkt,lucasallan/rkt,squeed/rkt,monstermunchkin/rkt,sgotti/rkt,coreos/rkt,matthaias/rkt,achanda/rkt,monstermunchkin/rkt,intelsdi-x/rkt,jakon89/rkt,yifan-gu/rocket,shobhit85/rkt,dgonyeo/rkt,yifan-gu/rkt,Wilybald/rkt,nhlfr/rkt,jjlakis/rkt,jonboulle/rkt,mike1729/rkt,alban/rkt,matthaias/rkt,jonboulle/rkt,Shashwatsh/rkt,shobhit85/rkt,Wilybald/rkt,sstabellini/rkt,sgotti/rkt,yifan-gu/rocket,Shashwatsh/rkt,ybubnov/rkt,tmrts/rkt,yifan-gu/rkt,joshix/rkt,nhlfr/rkt,squeed/rkt,dgonyeo/rkt,cab105/rkt,matthaias/rkt,nhlfr/rkt,monstermunchkin/rkt,sstabellini/rkt,jjlakis/rkt,alban/rkt,coreos/rkt,Wilybald/rkt,rkt/rkt,kinvolk/rkt,akshaykarle/rkt,cab105/rkt,jonboulle/rkt,achanda/rkt,intelsdi-x/rkt,mike1729/rkt,akshaykarle/rkt,Wilybald/rkt,rkt/rkt,ybubnov/rkt,jakon89/rkt,joshix/rkt,akshaykarle/rkt,kinvolk/rkt,joshix/rkt,rkt/rkt,joshix/rkt,dgonyeo/rkt,euank/rkt,shobhit85/rkt,jjlakis/rkt,kinvolk/rkt,sstabellini/rkt,squeed/rkt,intelsdi-x/rkt,sgotti/rkt,s-urbaniak/rkt,s-urbaniak/rkt