[IMP] convert to opporunity on phone call fix

bzr revid: fp@openerp.com-20130225164616-v3bu51s277sto15j

addons/crm/crm_phonecall_view.xml

@@ -152,7 +152,7 @@
                     name="action_button_convert2opportunity"
                     states="open,pending"
                     icon="gtk-index"
-                    type="action" attrs="{'invisible':[('opportunity_id','!=',False)]}"/>
+                    type="object" attrs="{'invisible':[('opportunity_id','!=',False)]}"/>
             </tree>
         </field>
     </record>