[FIX] purchase_double_validation: do not update limit on module update

In the module `purchase_double_validation`,
you can change the limit to require a second approval
in the purchase settings.

If the module was updated, the limit was re-set to
its default value.

Closes #4183

addons/purchase_double_validation/purchase_double_validation_workflow.xml

@@ -23,7 +23,6 @@
         <record id="trans_confirmed_double_gt" model="workflow.transition">
             <field name="act_from" ref="act_double_check"/>
             <field name="act_to" ref="act_double_wait"/>
-            <field name="condition">amount_untaxed &gt;= 5000</field>
             <field name="signal">purchase_approve</field>
             <field name="group_id" ref="purchase.group_purchase_manager"/>
         </record>
@@ -31,7 +30,6 @@
         <record id="trans_confirmed_double_lt" model="workflow.transition">
             <field name="act_from" ref="act_double_check"/>
             <field name="act_to" ref="act_double_wait"/>
-            <field name="condition">amount_untaxed &lt; 5000</field>
         </record>
 
         <record id="trans_double_app_conf" model="workflow.transition">
@@ -40,4 +38,12 @@
         </record>
 
     </data>
+    <data noupdate="1">
+        <record id="trans_confirmed_double_gt" model="workflow.transition">
+            <field name="condition">amount_untaxed &gt;= 5000</field>
+        </record>
+        <record id="trans_confirmed_double_lt" model="workflow.transition">
+            <field name="condition">amount_untaxed &lt; 5000</field>
+        </record>
+    </data>
 </openerp>