Use negative col attribute

issue2090
review33661002

view/production_form.xml

@@ -42,7 +42,7 @@ this repository contains the full copyright notices and license terms. -->
     <group col="4" colspan="4" id="state_buttons">
         <label name="state"/>
         <field name="state"/>
-        <group col="7" colspan="2" id="buttons">
+        <group col="-1" colspan="2" id="buttons">
             <button name="cancel" string="Cancel"
                 icon="tryton-cancel"/>
             <button name="draft" string="Draft"/>