Bug 9742: Does not display the popup on creating new record

The new confirmation on starting a z39.50 serach in cataloguing always
pops up, even when you are working on a new record that has not been
saved yet.

Test plan:
1/ Edit an existing record, click on the Z3950 search button, confirm
the popup appears.
2/ Create a new record, click on the Z3950 search button, confirm
the popup does not appear.

Followed test plan. Works as expected.
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>

Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>
Works as expected, Gustavo (librarian) convinced me that "it doesn't
hurt that much" with the test for new record. Happy easter :-D

(cherry picked from commit f0711f0d0d)
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>

koha-tmpl/intranet-tmpl/prog/en/modules/cataloguing/addbiblio.tt

@@ -69,10 +69,15 @@
             }
         });
 
+        [%# Only ask for a confirmation if it is an edit %]
         $("#z3950search").click(function(){
-            if (confirm(_("Please note that this external search could replace the current record."))){
+            [% IF biblionumber %]
+                if (confirm(_("Please note that this external search could replace the current record."))){
+                    PopupZ3950();
+                }
+            [% ELSE %]
                 PopupZ3950();
-            }
+            [% END %]
         });
 
         $("#saverecord").click(function(){