Add missing last_timestamp label in sequence form view

issue2630

trytond/ir/sequence.xml

@@ -39,6 +39,7 @@ this repository contains the full copyright notices and license terms. -->
                         <field name="timestamp_rounding"/>
                         <label name="timestamp_offset"/>
                         <field name="timestamp_offset"/>
+                        <label name="last_timestamp"/>
                         <field name="last_timestamp"/>
                     </group>
                     <separator string="Legend (Placeholders for prefix, suffix)" colspan="4"