Fixes #5061: Fix Effect Rack View in Instrument

The EffectRackView in an InstrumentTrackWindow had some parts hidden when
loading files with >= 4 effects. This was now fixed by force-resizing the
EffectRackView to its desired size.

It's a dirty fix, but good enough, plus many Instrument UIs might get
rewritten to be resizable in the future.

src/tracks/InstrumentTrack.cpp

@@ -1477,6 +1477,8 @@ InstrumentTrackWindow::InstrumentTrackWindow( InstrumentTrackView * _itv ) :
 	adjustTabSize(m_ssView);
 	adjustTabSize(instrumentFunctions);
 	adjustTabSize(m_effectView);
+	// stupid bugfix, no one knows why
+	m_effectView->resize(INSTRUMENT_WIDTH - 4, INSTRUMENT_HEIGHT - 4 - 1);
 	adjustTabSize(m_midiView);
 	adjustTabSize(m_miscView);