Bug 39603: Make sure authorised value category is ITEMTYPECAT

To test:
1. Add some AVs for ITEMTYPECAT and set some of your item types to be in that Search category. I made one called OTHER
2. Go to the OPAC advanced search page, the item types should be correctly displaying under ITEMTYPECAT with the correct description from ITEMTYPECAT.
3. Create a new AV called OTHER in a different category like 'ERM_AGREEMENT_CLOSURE_REASON'. Make the description something different like 'Wrong description'.
4. Now go back to the OPAC advanced search.
5. Notice your OTHER option now reads 'Wrong description'.
6. APPLY PATCH and restart_all
7. Try again, the OPAC descriptions should now be correct.

Signed-off-by: Eric Phetteplace <phette23@gmail.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
(cherry picked from commit f79aec38b8)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>

C4/Koha.pm

@@ -101,6 +101,7 @@ sub GetItemTypesCategorized {
         FROM itemtypes
         LEFT JOIN authorised_values ON searchcategory = authorised_value
         WHERE searchcategory > '' and hideinopac=1
+        AND category = 'ITEMTYPECAT'
         UNION
         SELECT DISTINCT searchcategory AS `itemtype`,
                         COALESCE(authorised_values.lib_opac,authorised_values.lib) AS description,
@@ -109,6 +110,7 @@ sub GetItemTypesCategorized {
         FROM itemtypes
         LEFT JOIN authorised_values ON searchcategory = authorised_value
         WHERE searchcategory > '' and hideinopac=0
+        AND category = 'ITEMTYPECAT'
         |;
 return ($dbh->selectall_hashref($query,'itemtype'));
 }