Minor "fix" to prevent vandals from getting 500 errors when passing in bogus "size" parameters to show_image.
Minor "fix" to prevent vandals from getting 500 errors when passing in bogus "size" parameters to show_image.


MushroomObserver/mushroom-observer,pellaea/mushroom-observer,raysuelzer/mushroom-observer,JoeCohen/mushroom-observer,raysuelzer/mushroom-observer,pellaea/mushroom-observer,MushroomObserver/mushroom-observer,MushroomObserver/mushroom-observer,MushroomObserver/mushroom-observer,pellaea/mushroom-observer,raysuelzer/mushroom-observer,MushroomObserver/mushroom-observer,JoeCohen/mushroom-observer,JoeCohen/mushroom-observer,raysuelzer/mushroom-observer,pellaea/mushroom-observer,pellaea/mushroom-observer,raysuelzer/mushroom-observer,JoeCohen/mushroom-observer,MushroomObserver/mushroom-observer,pellaea/mushroom-observer,raysuelzer/mushroom-observer,pellaea/mushroom-observer,MushroomObserver/mushroom-observer,raysuelzer/mushroom-observer,JoeCohen/mushroom-observer,JoeCohen/mushroom-observer,JoeCohen/mushroom-observer