qt: Fix erroneous reuse of JobPrivate objects

* lang/qt/src/job.cpp (Job::~Job): Destroy JobPrivate object belonging
to destroyed job.
--

In some tests different Job objects reused the same JobPrivate object
because they were created with the same memory address. Obviously, this
shouldn't happen.

GnuPG-bug-id: 5739

lang/qt/src/job.cpp

@@ -105,6 +105,7 @@ QGpgME::Job::Job(QObject *parent)
 
 QGpgME::Job::~Job()
 {
+    ::d_func()->erase(this);
 }
 
 QString QGpgME::Job::auditLogAsHtml() const