Bug 19706: Fix bad json formed when there are no CCODE values

To test:
1 - Delete all ccode values in your system
2 - Load the item search page
3 - View the console and note a js error
4 - Try to perform an item search to screen
5 - Internal server error ("unsupported format 'html'" in logs)
6 - Apply patch
7 - Reload page
8 - Note js error is gone
9 - Perform search to screen, success!

To test there is no regression:
1 - Have some values in CCODE authorised values
2 - Ensure collection drop down on item search displays correctly
3 - Ensure item search returns results ot screen with no js errors

Signed-off-by Owen Leonard <oleonard@myacpl.org>

Signed-off-by: David Bourgault <david.bourgault@inlibro.com>

Signed-off-by: Josef Moravec <josef.moravec@gmail.com>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>

koha-tmpl/intranet-tmpl/prog/en/modules/catalogue/itemsearch.tt

@@ -363,7 +363,11 @@
                     { 'type': 'text' },
                     { 'type': 'text' },
                     { 'type': 'text' },
-          { 'type': 'select', 'values': [% ccodes.json %] },
+                    [% IF ccodes.size %]
+                        { 'type': 'select', 'values': [% ccodes.json %] },
+                    [% ELSE %]
+                        null,
+                    [% END %]
                     { 'type': 'text' },
                     { 'type': 'text' },
                     { 'type': 'select', 'values': [% branches.json %] },