Fix release links creation

6 jobs for v2020.09.27 in 38 minutes and 46 seconds (queued for 2 seconds)
Name Stage Failure
publish Publish
You are about to publish a box on Vagrant Cloud with the following options:
archlinux/archlinux: (vv2020.09.27) for provider 'libvirt'
Automatic Release: true
==> cloud: Creating a box entry...
==> cloud: Box already exists, updating instead...
==> cloud: Creating a version entry...
Failed to create box archlinux/archlinux
Invalid version given: v2020.09.27
ERROR: Job failed: exit code 1