[FIX] hr_expense: fix alias_domain configuration

Before this commit, if hr_expense module was installed it was
impossible to configure alias_domain in the settings, the change
wasn't taken into account. This was due to the presence of the
field at two separate place and one of them having the readonly
parameter set.
This commit fix this issue that was introduced by :
5eca7b7378

Task-3127163

closes odoo/odoo#112443

X-original-commit: fc1c20cb5ce471b65120ec3eff7abd18ffd3a9fb
Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>

addons/hr_expense/views/res_config_settings_views.xml

@@ -17,7 +17,7 @@
                                         <label for="hr_expense_alias_prefix" string="Alias" class="o_light_label"/>
                                         <field name="hr_expense_alias_prefix" class="oe_inline"/>
                                         <span>@</span>
-                                        <field name="alias_domain" class="oe_inline" readonly="1"/>
+                                        <field name="alias_domain" class="oe_inline" readonly="1" force_save="1"/>
                                     </div>
                                 </div>
                                 <div class="content-group" attrs="{'invisible': ['|', ('hr_expense_use_mailgateway', '=',  False), ('alias_domain', 'not in', ['localhost', '', False])]}">