fixed bug when loading a map with no channels
fixed bug when loading a map with no channels

sdss/marvin,albireox/marvin,sdss/marvin,sdss/marvin,bretthandrews/marvin,bretthandrews/marvin,albireox/marvin,sdss/marvin,bretthandrews/marvin,albireox/marvin,bretthandrews/marvin,albireox/marvin