[FIX] hr_holidays: date_from field

Wrong field date_from:month in model hr.holidays

opw:676837

addons/hr_holidays/hr_holidays_view.xml

@@ -53,7 +53,7 @@
                         <filter string="Manager" context="{'group_by':'manager_id'}"/>
                         <filter name="group_type" string="Type" context="{'group_by':'holiday_status_id'}"/>
                         <separator/>
-                        <filter name="group_date_from" string="Start Month" context="{'group_by':'date_from:month'}"/>
+                        <filter name="group_date_from" string="Start Month" context="{'group_by':'date_from'}"/>
                     </group>
                 </search>
             </field>