cpp: Add missing transition, remove two ignored (and wrong) transitions

* lang/cpp/src/gpgsignkeyeditinteractor.cpp (makeTable): Remove two
transitions.  Add one transition.
* lang/cpp/src/gpgsignkeyeditinteractor.cpp (makeTable)
<sign_uid.dupe_okay>: Add one more transition.

This adds a missing transition for the CONFIRM2 state which ensures
that the certification is properly completed in case two confirmations
were requested. And it removes two useless (and wrong) transitions
which are overwritten by two later correct transitions in the map.

This is gpgmepp commit 5b77f4072d03342b8719bbe93fc77641fffb476a

The second patch fixed a bug seen before we could test Ingo's
patch. - wk

• GnuPG-bug-id: T7600