fixed 'distanceFromSource' test broken by !== change
fixed 'distanceFromSource' test broken by !== change

radiasoft/sirepo,mkeilman/sirepo,mrakitin/sirepo,radiasoft/sirepo,mrakitin/sirepo,mkeilman/sirepo,mkeilman/sirepo,mrakitin/sirepo,radiasoft/sirepo,radiasoft/sirepo,mkeilman/sirepo,mrakitin/sirepo,radiasoft/sirepo