[FIX] IntegrityError: column "lastname" contains null values

when creating or copying users

partner_firstname/partner.py

@@ -99,6 +99,7 @@ class ResPartner(orm.Model):
         to_use = vals
         if 'name' in vals:
             corr_vals = vals.copy()
+            if vals.get('name'):
                 corr_vals['lastname'] = corr_vals['name']
             del(corr_vals['name'])
             to_use = corr_vals