Only notify qa-alerts (drops qa list)

The QA is for human beings, only send beta jobs failures on the recently
created qa-alerts list.

Updates:
    beta-code-update-eqiad
    beta-mediawiki-config-update-eqiad
    beta-scap-eqiad

Change-Id: Id96e9202c1b0be53b5541bf72fcc91a9b666ee86