Double call of language_select_form() throws error (bug #1286941)

Some things like die_info() will try and create a smarty() call when
we are already in one, which causes language_select_form() to throw
headdata error as it is called twice and can't be due to the form
having a select field in it and select fields love to add data to the
$HEADDATA.

Made it so that it is only called once.

Change-Id: Ie2099dfc1990c8bd2a039bdd33869d9b65c156f1
Signed-off-by: Robert Lyon <robertl@catalyst.net.nz>