[mythtv] Qt warnings on mythfrontend start

[Klaas de Waal]

Hi,

With today's master I get the following warning on start of
mythfrontend (3 lines before and 1 line after also shown):

2020-01-04 16:55:34.268534 I  Checking for theme updates every hour
2020-01-04 16:55:34.268722 I  Registering HouseKeeperTask 'HardwareProfiler'.
2020-01-04 16:55:34.269404 I  Starting HouseKeeper.
Attempted flush to non-raster surface QWidgetWindow(0x131d220,
name="mainwindowWindow") of type QSurface::OpenGLSurface (consider
using Qt::WA_PaintOnScreen to exclude from backingstore sync)
Attempted flush to non-raster surface QWidgetWindow(0x131d220,
name="mainwindowWindow") of type QSurface::OpenGLSurface (consider
using Qt::WA_PaintOnScreen to exclude from backingstore sync)
2020-01-04 16:55:34.433313 I  Bonjour: Service registration complete:
name 'Mythfrontend on modu' type '_mythfrontend._tcp.' domain:
'local.'

This is with mythfrontend running in  a 1280x720 window on a 1920x1200
screen, Intel graphics only.

Groetjes,
Klaas.