[CentOS] ntp update version

I noticed that although I'd fetched the latest update to ntp from the
mirror it wasn't being installed.

It seems that the version numbers have got out of step.  According to
the changelog the update that was released in August should have had
the version number 4.2.0.a.20040617-8.el4_7.2, whereas in CentOS it's
actually 4.2.0.a.20040617-8.el4_8.2.

The changelog says the latest update is 4.2.0.a.20040617-8.el4_8.1,
which is what CentOS has, but that's a lower version than the August
update.

Ron