QQuickWindow: don't leak old screenChanged connections

Connections could accumulate. Because the newest one was invoked
last due to how signal-slot invocations are ordered, rendering
was correct, but the stale connections caused unnecessary updates
(and wasted a small amount of memory).
This comes from a misunderstanding I had at the time about how
QMetaObject::Connection works. Destroying or overwriting one does
not affect the actual connection.

While at it, also modernize the connect().

Change-Id: Idde81bdbff8947ed517bf2740d623a395c0acb74
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
(cherry picked from commit 9f8292d48913c5bc50377749c2b3e030cf16d703)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

0 files changed, 0 insertions, 0 deletions