Remove notes from CVE-2008-3793

It was determined by MITRE that this is a duplicate candidate of
CVE-2008-3792. It is unclear if this really is the case as CVE-2008-3792
was for the Linux kernel issue in sctp.

But as MITRE explicitly rejected CVE-2008-3793 rejected as a duplication
of something else, let's remove the notes and follow that claim. It has
of no practical impact for Debian security here as Adobe Flash Player is
marked anyway as NFU.