Clean up plugin::modelFromJson() "Could not find module" message.

src/patch.cpp

@@ -455,6 +455,7 @@ json_t* Manager::toJson() {
 
 void Manager::fromJson(json_t* rootJ) {
 	clear();
+	warningLog = "";
 
 	// version
 	std::string version;

src/plugin.cpp

@@ -398,7 +398,7 @@ Model* modelFromJson(json_t* moduleJ) {
 	// Get Model
 	Model* model = getModelFallback(pluginSlug, modelSlug);
 	if (!model)
-		throw Exception("Could not find module \"%s\" \"%s\"", pluginSlug.c_str(), modelSlug.c_str());
+		throw Exception("Could not find module %s/%s", pluginSlug.c_str(), modelSlug.c_str());
 	return model;
 }