Remove some superfluous qApp->processEvents().

This shouldn't be there, as it forces event handling in certain
situations which break other parts of the UI event handling. We
experienced a missing redraw which caused hacky workarounds.

Change-Id: I2185ecb1b99d1ff20caa9a08637d77100e520445
Reviewed-by: Niels Weber <niels.weber@digia.com>
Reviewed-by: Kai Koehne <kai.koehne@digia.com>