[FIX] stock: Customer address in delivery slip report

When printing the delivery slip in dropshipping, the displayed address in the
delivery slip report must be the address of the customer. Inspired from report.picking

opw:695865

addons/stock/report/report_deliveryslip.xml

@@ -12,7 +12,7 @@
                                 <span><strong>Customer Address:</strong></span>
                             </div>
                             <div t-if="o.partner_id" name="partner_header">
-                                <div t-field="o.partner_id"
+                                <div t-field="o.move_lines[0].partner_id"
                                    t-field-options='{"widget": "contact", "fields": ["address", "name", "phone", "fax"], "no_marker": true}'/>
                             </div>
                         </div>