MidiOss: Fix a typo which breaks build

src/core/midi/MidiOss.cpp

@@ -40,7 +40,7 @@ MidiOss::MidiOss() :
 	// only start thread, if opening of MIDI-device is successful,
 	// otherwise isRunning()==false indicates error
 	if( m_midiDev.open( QIODevice::ReadWrite |
-		QIODevice::Unbuffered ) ) ||
+		QIODevice::Unbuffered ) ||
 		m_midiDev.open( QIODevice::ReadOnly |
 			QIODevice::Unbuffered ) )
 	{