Fix travis nightly to push from main. (#1655)
Fix travis nightly to push from main. (#1655)

We renamed the branch, but the release was looking for master. This
fixes travis to look for main.

Signed-off-by: Alexander Wels <4461831985d22a9cb5876dee61b80a0160999dcb@redhat.com>
kubevirt/containerized-data-importer,kubevirt/containerized-data-importer,kubevirt/containerized-data-importer