Ensure Shader disconnects the destroyed listener from the context

cleanup() is never called. The signal must be disconnected nonetheless,
otherwise bad things can happen. For example, with a Scene3D in a
QQuickWidget the context will be destroyed at a different stage than with
QQuickWindow, and Shader may already be destroyed at that stage.

Task-number: QTBUG-52132
Change-Id: Icbc8fe0294e0fa6a33385f7d9a2f81ef9f514283
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>

0 files changed, 0 insertions, 0 deletions