Fix default value of RelationField

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@14139 20353a03-c40f-0410-a6d1-a30d3c3de9de

bt5/erp5_accounting/SkinTemplateItem/portal_skins/erp5_accounting/PurchaseInvoiceTransaction_viewDetails/my_source_section_title.xml

@@ -403,9 +403,7 @@
                 </item>
                 <item>
                     <key> <string>default</string> </key>
-                    <value>
-                      <list/>
-                    </value>
+                    <value> <string></string> </value>
                 </item>
                 <item>
                     <key> <string>description</string> </key>

bt5/erp5_accounting/bt/revision

-257
\ No newline at end of file
+259
\ No newline at end of file