qt5enginio: bump to 1.6.3

Qt Enginio has been bumped to 1.6.3 with Qt 5.6.3.

This new version follows the Qt release number and has only one change
since 1.6.2[1].

[1]: https://github.com/qt/qtenginio/commit/e447818458c9211e95ee5e75e294f76b6abf32d4



Signed-off-by: Gaël PORTAY <gael.portay@savoirfairelinux.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>