FIX l10n_it_fatturapa_in when writing attachment name without file

Steps:
1 - Accounting → Purchases → Incoming E-Bill Files
2 - Click on Create
3 - Fill in Attachment Name
4 - Click Save

File "/home/odoo/build/OCA/l10n-italy/l10n_it_fatturapa/models/ir_attachment.py", line 117, in get_xml_string
if fatturapa_attachment.datas_fname.lower().endswith('.p7m'):
AttributeError: 'bool' object has no attribute 'lower'

l10n_it_fatturapa_in/views/account_view.xml

@@ -17,7 +17,7 @@
                                        attrs="{'invisible': [('id', '=', False)]}"/>
                             </div>
                             <field name="datas_fname" invisible="1"></field>
-                            <field name="name"></field>
+                            <field name="name" invisible="1"></field>
                         </group>
                         <group>
                             <field name="xml_supplier_id"/>