Fix crash on rotation jobs

We don't need to delete the threadweaver job, threadweaver does it by itself,
and if we call deleteLater it may happen that the main thread deletes it
and then when the threadweaver thread tries to call the delete things are
gone and it goes kaboom

BUGS: 382725

core/pagecontroller.cpp

@@ -43,8 +43,6 @@ void PageController::imageRotationDone(const ThreadWeaver::JobPointer &j)
 
         emit rotationFinished( job->page()->m_number, job->page()->m_page );
     }
-
-    job->deleteLater();
 }
 
 #include "moc_pagecontroller_p.cpp"