The owner address for the starlingx-discuss list on
lists.starlingx.io has started receiving large volumes of
unsolicited messages unrelated to its intended purpose. As there's
no easy way to discern them from legitimate messages, we'll do the
same as we've done for other owner addresses and reject them with a
brief error explaining the situation.
Change-Id: I95a910c2e6206098ca268a0e10e86b66455ad1bd
159f012d47