Fix #574 - Allow build to continue if icon conversion fails (PR#585)
Fix #574 - Allow build to continue if icon conversion fails (PR#585)

By unsetting `options.icon` if input cannot be converted.
jiahaog/Nativefier,jiahaog/Nativefier,gfpacheco/Nativefier,skewedlines/Nativefier,gfpacheco/Nativefier,gfpacheco/Nativefier,skewedlines/Nativefier,skewedlines/Nativefier,jiahaog/Nativefier