Fix virtual camera action selection causing a crash

The Create() and Copy() functions were not correctly implemented and
returned a nullptr

lib/macro/macro-tab.cpp

@@ -13,6 +13,7 @@
 #include "utility.hpp"
 #include "version.h"
 
+#include <obs-frontend-api.h>
 #include <QColor>
 #include <QGraphicsOpacityEffect>
 #include <QMenu>
@@ -729,6 +730,7 @@ void AdvSceneSwitcher::MacroSelectionChanged()
 		return;
 	}
 	SetEditMacro(*macro);
+	obs_frontend_save();
 }
 
 void AdvSceneSwitcher::HighlightOnChange()

lib/variables/variable-tab.cpp

@@ -102,7 +102,6 @@ static void removeVariableRow(QTableWidget *table, const QString &name)
 
 static void updateVaribleStatus(QTableWidget *table)
 {
-	auto lock = LockContext();
 	for (int row = 0; row < table->rowCount(); row++) {
 		auto item = table->item(row, 0);
 		if (!item) {

plugins/base/macro-action-virtual-cam.cpp

@@ -67,12 +67,12 @@ bool MacroActionVCam::Load(obs_data_t *obj)
 
 std::shared_ptr<MacroAction> MacroActionVCam::Create(Macro *m)
 {
-	return std::shared_ptr<MacroAction>();
+	return std::make_shared<MacroActionVCam>(m);
 }
 
 std::shared_ptr<MacroAction> MacroActionVCam::Copy() const
 {
-	return std::shared_ptr<MacroAction>();
+	return std::make_shared<MacroActionVCam>(*this);
 }
 
 static inline void populateActionSelection(QComboBox *list)

plugins/base/macro-condition-audio.cpp

@@ -67,7 +67,7 @@ bool MacroConditionAudio::CheckOutputCondition()
 	OBSSourceAutoRelease source =
 		obs_weak_source_get_source(_audioSource.GetSource());
 
-	double curVolume = _useDb ? _peak : DecibelToPercent(_peak);
+	double curVolume = _useDb ? _peak : DecibelToPercent(_peak) * 100;
 
 	switch (_outputCondition) {
 	case OutputCondition::ABOVE: