pgsql: Don't qualify type pg_catalog.text inextend-extensions-example.

Don't qualify type pg_catalog.text in extend-extensions-example.

Extension scripts begin execution with pg_catalog at the front of the
search path, so type names reliably refer to pg_catalog.  Remove these
superfluous qualifications.  Earlier <programlisting> of this <sect1>
already omitted them.  Back-patch to 9.3 (all supported versions).

Branch
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REL9_4_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/60c623678fde2c6bc331c11197e457ba69170b50

Modified Files
--------------
doc/src/sgml/extend.sgml | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)