pgsql: Remove TZ environment-variable entry from postgres reference pag

Remove TZ environment-variable entry from postgres reference page.

The server hasn't paid attention to the TZ environment variable since
commit ca4af308c32d03db, but that commit missed removing this documentation
reference, as did commit d883b916a947a3c6 which added the reference where
it now belongs (initdb).

Back-patch to 9.2 where the behavior changed.  Also back-patch
d883b916a947a3c6 as needed.

Matthew Somerville

Branch
------
REL9_2_STABLE

Details
-------
http://git.postgresql.org/pg/commitdiff/e19b7f7c8bfb41899bdfa386049a0e2490ea6a79

Modified Files
--------------
doc/src/sgml/ref/initdb.sgml       | 11 +++++++++++
doc/src/sgml/ref/postgres-ref.sgml | 10 ----------
2 files changed, 11 insertions(+), 10 deletions(-)