Include the period in the nested part when searching the invoice party of lines

Closes #14125
(grafted from d582b659c4bc7fde91efcb84d067351552cfdd5c)

--HG--
branch : 7.0

modules/account_invoice/invoice.py

@@ -2356,7 +2356,7 @@ class InvoiceLine(sequence_ordered(), ModelSQL, ModelView, TaxableMixin):
 
     @classmethod
     def search_invoice_party(cls, name, clause):
-        nested = clause[0][len(name) + 1:]
+        nested = clause[0][len(name):]
         return ['OR',
             ('invoice.party' + nested, *clause[1:]),
             ('party' + nested, *clause[1:]),