Bump qtx11extras version to 5.3.0

Change-Id: Ia76fecdcc02044219fee9d2cd492f05630995000
Reviewed-by: David Faure <david.faure@kdab.com>
Merge remote-tracking branch 'origin/stable' into dev

Change-Id: I1a43928ab6b5c1458c1f662896e022b24bf38ee1
Merge remote-tracking branch 'origin/stable' into dev

Change-Id: I39296b426d6e7555db5087e720066fad02ffc5d3
Merge remote-tracking branch 'origin/stable' into dev

Change-Id: I1155f08deee98516e021a21c54132292d27aabdc
Merge remote-tracking branch 'origin/stable' into dev

Conflicts:
	.qmake.conf

Change-Id: Icab7fb1dd11851639a46b2cb211ded5df92a1dbe
Merge remote-tracking branch 'origin/stable' into dev

Conflicts:
	.qmake.conf

Change-Id: I9b3732bd9c128ec862b0b9a91881f44322142479