Remove redundant LV2Ports::Audio::m_optional

The same info is already stored in the `Lv2Ports::Meta` base class.

include/Lv2Ports.h

@@ -162,7 +162,7 @@ struct Cv : public VisitablePort<Cv, ControlPortBase>
 
 struct Audio : public VisitablePort<Audio, PortBase>
 {
-	Audio(std::size_t bufferSize, bool isSidechain, bool isOptional);
+	Audio(std::size_t bufferSize, bool isSidechain);
 
 	//! Copy buffer passed by LMMS into our ports
 	//! @param channel channel index into each sample frame

src/core/lv2/Lv2Ports.cpp

@@ -201,8 +201,8 @@ QString PortBase::uri() const
 
 
 
-Audio::Audio(std::size_t bufferSize, bool isSidechain, bool isOptional)
-	: m_buffer(bufferSize), m_sidechain(isSidechain), m_optional(isOptional)
+Audio::Audio(std::size_t bufferSize, bool isSidechain)
+	: m_buffer(bufferSize), m_sidechain(isSidechain)
 {
 }
 

src/core/lv2/Lv2Proc.cpp

@@ -56,8 +56,7 @@ Plugin::PluginTypes Lv2Proc::check(const LilvPlugin *plugin,
 		bool portMustBeUsed =
 			!portIsSideChain(plugin,
 							lilv_plugin_get_port_by_index(plugin, portNum)) &&
-			!portIsOptional(plugin,
-							lilv_plugin_get_port_by_index(plugin, portNum));
+			!meta.m_optional;
 		if (meta.m_type == Lv2Ports::Type::Audio && portMustBeUsed)
 			++audioChannels[meta.m_flow == Lv2Ports::Flow::Output
 				? outCount : inCount];
@@ -381,8 +380,7 @@ void Lv2Proc::createPort(std::size_t portNum)
 				new Lv2Ports::Audio(
 						static_cast<std::size_t>(
 							Engine::mixer()->framesPerPeriod()),
-						portIsSideChain(m_plugin, lilvPort),
-						portIsOptional(m_plugin, lilvPort)
+						portIsSideChain(m_plugin, lilvPort)
 					);
 			port = audio;
 			break;