[FIX] base: fix display of creation info in form view

Currently when creating an attachment in backend, history section holds
a "Creation: on" void line that is populated after create with "creation:
administator on 2019..." . This is quite ugly and not usability oriented.

Let us hide the history line while create information are not set, aka
before first save of record.

closes odoo/odoo#37940

X-original-commit: 9ef4cb3ada349b34ba8a5daa5ca9f9765bc43437
Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>

odoo/addons/base/views/ir_attachment_views.xml

@@ -25,7 +25,7 @@
                             <field name="company_id" groups="base.group_multi_company" options="{'no_create': True}"/>
                             <field name="public"/>
                         </group>
-                        <group string="History" groups="base.group_no_one">
+                        <group string="History" groups="base.group_no_one" attrs="{'invisible':[('create_date','=',False)]}">
                             <label for="create_uid" string="Creation"/>
                             <div name="creation_div">
                                 <field name="create_uid" readonly="1" class="oe_inline"/> on