Fix bogus tab-completion rule for CREATE PUBLICATION.

Fix bogus tab-completion rule for CREATE PUBLICATION.

You can't use "FOR TABLE" as a single Matches argument, because readline
will consider that input to be two words not one.  It's necessary to make
the pattern contain two arguments.

The case accidentally worked anyway because the words_after_create
test fired ... but only for the first such table name.

Noted by Edmund Horner, though this isn't exactly his proposed fix.
Backpatch to v10 where the faulty code came in.

Discussion: https://postgr.es/m/CAMyN-kDe=gBmHgxWwUUaXuwK+p+7g1vChR7foPHRDLE592nJPQ@mail.gmail.com