ERP5Site: Disable order support.

It is easy to see contents ordered by id by default in ERP5Site.
7 jobs for master in 0 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  External
passed ERP5.CodingStyleTest-Master

00:56:39

passed ERP5.PerformanceTest-Master

00:26:57

failed ERP5.UnitTest-Master

01:38:24

failed ERP5.UnitTest-Zope2

03:51:06

passed SlapOS.Eggs.UnitTest-Master.Python2

00:13:50

passed SlapOS.Eggs.UnitTest-Master.Python3

00:20:46

passed Wendelin.UnitTest-Master

03:55:34