Bug 16857 - patron-attr-types.tt: Get rid of warnings "Argument "" isn't numeric"

To vrify:
- Go to Home > Administration > Patron attribute types
- Make sure you have some patron attribute types with no branches limitation
- For each attribute type you get a warning in intranet-error.log:
patron-attr-types.pl: Argument "" isn't numeric in numeric gt (>) at (...)/koha-tmpl/intranet-tmpl/prog/en/modules/admin/patron-attr-types.tt line 284.

To test:
- Appy patch
- Verify that warnings no longer appear in intranet-error.log

Signed-off-by: Srdjan <srdjan@catalyst.net.nz>

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

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
(cherry picked from commit abb7980004)
Signed-off-by: Frédéric Demians <f.demians@tamil.fr>
(cherry picked from commit dc6ea8d5c9)
Signed-off-by: Julian Maurice <julian.maurice@biblibre.com>

koha-tmpl/intranet-tmpl/prog/en/modules/admin/patron-attr-types.tt

@@ -303,7 +303,7 @@ function CheckAttributeTypeForm(f) {
             <td>[% item.code |html %]</td>
             <td>[% item.description %]</td>
             <td>
-                [% IF item.branches.size > 0 %]
+                [% IF ( item.branches.size && item.branches.size > 0 ) %]
                     [% branches_str = "" %]
                     [% FOREACH branch IN item.branches %]
                         [% branches_str = branches_str _ " " _ branch.branchname _ "(" _ branch.branchcode _ ")" %]