ERP5/Extensions: Remove unused Extension untouched for years

See merge request !1244
5 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
passed ERP5.CodingStyleTest-Master

00:42:27

passed ERP5.UnitTest-Master

01:14:38

failed ERP5.UnitTest-Master.Medusa

01:21:49

passed SlapOS.Eggs.UnitTest-Master.Python2

00:27:27

passed SlapOS.Eggs.UnitTest-Master.Python3

00:09:50