erp5_project: use Base_viewFieldLibrary for forum link field

bt5/erp5_project/SkinTemplateItem/portal_skins/erp5_project/Project_view/my_forum_link_url_string.xml

@@ -73,11 +73,11 @@
               <dictionary>
                 <item>
                     <key> <string>field_id</string> </key>
-                    <value> <string>my_view_mode_email_url_string</string> </value>
+                    <value> <string>my_string_field</string> </value>
                 </item>
                 <item>
                     <key> <string>form_id</string> </key>
-                    <value> <string>Base_viewBaseFieldLibrary</string> </value>
+                    <value> <string>Base_viewFieldLibrary</string> </value>
                 </item>
                 <item>
                     <key> <string>target</string> </key>