Fix usage of Many2Many in test XML

trytond/test/sequence.xml

@@ -7,7 +7,11 @@ this repository contains the full copyright notices and license terms. -->
         <record model="ir.sequence.type" id="sequence_type_test">
             <field name="name">Test</field>
             <field name="code">test</field>
-            <field name="groups" eval="[('add', ref('res.group_admin'))]"/>
+        </record>
+        <record model="ir.sequence.type-res.group"
+            id="sequence_type_test_group_admin">
+            <field name="sequence_type" ref="sequence_type_test"/>
+            <field name="group" ref="res.group_admin"/>
         </record>
 
     </data>