when clear()ing, also disable FX-chain (closes #1994482)

git-svn-id: https://lmms.svn.sf.net/svnroot/lmms/trunk/lmms@1176 0778d3d1-df1d-0410-868b-ea421aaaa00d

src/core/effect_chain.cpp

@@ -247,6 +247,7 @@ bool effectChain::isRunning( void )
 
 void effectChain::clear( void )
 {
+	m_enabledModel.setValue( FALSE );
 	for( int i = 0; i < m_effects.count(); ++i )
 	{
 		delete m_effects[i];