Commit 6c3ffd69 added a couple new predefined roles but didn't properly
wrap the SQL commands mentioned in the description of those roles with
command tags, so add them now.

Backpatch-through: 14
Reported-by: Michael Banck
Discussion: https://postgr.es/m/606d8b1c.1c69fb81.3df04.1a99@mx.google.com