Prevent uninitialized var warnings in OpenILS::WWW::SuperCat::unapi

Prevent uninitialized var warnings in OpenILS::WWW::SuperCat::unapi

Given a tag URI like tag:localhost,2011:biblio-record_entry/1 with
no format, Evergreen was throwing uninitialized variable warnings
and attempting to invoke "open-ils.supercat..formats" due to the
unitialized $type variable, which resulted in an Apache error.

On the TT OPAC, this enables Zotero to successfully offer import
of all entries on the search results page. On the AjaxPAC, it seems
that Zotero parses the page before the unAPI hrefs have been supplied
by JavaScript.

Signed-off-by: Dan Scott <dan@coffeecode.net>
git-svn-id: svn://svn.open-ils.org/ILS/branches/rel_2_1@20391 dcc99617-32d9-48b4-a31d-7c20da2025e4