[Reportbug-maint] Bug#862095: reportbug: Bugs in backported packages must not be sent to the BTS

[Adrian Bunk]

Package: reportbug
Version: 6.6.3
Severity: serious

Bugs against backported packages (~bpo versions) are not allowed
to be reported to the BTS without explicit permission from the
maintainer to do so, and should instead automatically be sent
to debian-backports at lists.debian.org

Example for a bug that was wrongly sent to the BTS: #860147