Fix isExternal logic.
Fix isExternal logic.

flamilton/saveSvgAsPng,exupero/saveSvgAsPng,raiyankamal/saveSvgAsPng,zky829/saveSvgAsPng,bjpop/saveSvgAsPng,exupero/saveSvgAsPng,zky829/saveSvgAsPng,bjpop/saveSvgAsPng,raiyankamal/saveSvgAsPng,flamilton/saveSvgAsPng,cool-Blue/saveSvgAsPng,cool-Blue/saveSvgAsPng