[FIX] account_payment_group: Print draft payment group

If we try to print a draft payment group we receive a traceback error
because we have not set the document number yet. With this change
we are able to prind draft payments without error.

closes #299

X-original-commit: c7dd825
Signed-off-by: Katherine Zaoral <kz@adhoc.com.ar>

account_payment_group/__manifest__.py

@@ -2,7 +2,7 @@
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
 {
     "name": "Account Payment with Multiple methods",
-    "version": "15.0.1.1.0",
+    "version": "15.0.1.2.0",
     "category": "Accounting",
     "website": "www.adhoc.com.ar",
     "author": "ADHOC SA, AITIC S.A.S",

account_payment_group/views/report_payment_group.xml

@@ -24,7 +24,7 @@
         <field name="model">account.payment.group</field>
         <field name="binding_model_id" ref="model_account_payment_group"/>
         <field name="report_type">qweb-pdf</field>
-        <field name="print_report_name">(object.partner_type == 'supplier' and 'Orden de pago' or 'Recibo') + ' ' + object.document_number</field>
+        <field name="print_report_name">(object.partner_type == 'supplier' and 'Orden de pago' or 'Recibo') + ' ' + (object.document_number or 'Borrador')</field>
         <field name="report_name">account_payment_group.report_payment_group</field>
         <field name="report_file">account_payment_group.report_payment_group</field>
     </record>