Custombuild only gets mainline versions updates

Hi,

Every time I execute ./build update custombuild downloads the newest mainline versions of nginx, but I need the latest stable version.
And off course the latest version is now installed (1.14.2)
This still happens after I emptied my custom_versions.txt
Does anyone knows what to change of fix so custombuild will only look for stable updates?
Any help will be appreciated!

Regards,

Hindrik