Eliminate ifndefs in notifications_manager_linux

Telegram/SourceFiles/platform/linux/notifications_manager_linux_dummy.cpp

@@ -0,0 +1,40 @@
+
+/*
+This file is part of Telegram Desktop,
+the official desktop application for the Telegram messaging service.
+
+For license and copyright information please follow this link:
+https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
+*/
+#include "platform/linux/notifications_manager_linux.h"
+
+namespace Platform {
+namespace Notifications {
+
+bool SkipAudio() {
+	return false;
+}
+
+bool SkipToast() {
+	return false;
+}
+
+bool SkipFlashBounce() {
+	return false;
+}
+
+bool Supported() {
+	return false;
+}
+
+std::unique_ptr<Window::Notifications::Manager> Create(
+		Window::Notifications::System *system) {
+	if (IsWayland()) {
+		return std::make_unique<Window::Notifications::DummyManager>(system);
+	}
+
+	return nullptr;
+}
+
+} // namespace Notifications
+} // namespace Platform