officejs_support_request_ui_test: remove proxy role on ERP5Site_addManagerAclUserIfNotExisting

When this is called in the test suite, the current user is already
logged in as manager.

bt5/erp5_officejs_support_request_ui_test/SkinTemplateItem/portal_skins/erp5_officejs_support_request_test/ERP5Site_addManagerAclUserIfNotExisting.xml

@@ -52,14 +52,6 @@
             <key> <string>_params</string> </key>
             <value> <string></string> </value>
         </item>
-        <item>
-            <key> <string>_proxy_roles</string> </key>
-            <value>
-              <tuple>
-                <string>Manager</string>
-              </tuple>
-            </value>
-        </item>
         <item>
             <key> <string>id</string> </key>
             <value> <string>ERP5Site_addManagerAclUserIfNotExisting</string> </value>