MTimeSection logs uninitialized value

Class MTimeSection in jdebug contains two character pointer members, `scope` and `title`. `Scope` is initialized, and `title` is not. `Title` is logged when the `master` pointer is not set.

HPCC-12046 removed `title` as a constructor parameter. The corresponding member should be removed, and `scope` should be logged in its place from the destructor.