delete instrument-instance *after* removing all play-handles from mixer as several play-handle-methods rely on instrument - fixes crash when removing track while playing

git-svn-id: https://lmms.svn.sf.net/svnroot/lmms/trunk/lmms@924 0778d3d1-df1d-0410-868b-ea421aaaa00d

src/tracks/instrument_track.cpp

@@ -143,9 +143,9 @@ instrumentTrack::instrumentTrack( trackContainer * _tc ) :
 
 instrumentTrack::~instrumentTrack()
 {
-	delete m_instrument;
 	engine::getMixer()->removePlayHandles( this );
 	engine::getMixer()->getMIDIClient()->removePort( m_midiPort );
+	delete m_instrument;
 }