electron: API tray.destroy is not working

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• I have read the Contributing Guidelines for this project.
• I agree to follow the Code of Conduct that this project adheres to.
• I have searched the issue tracker for an issue that matches the one I want to file, without success.

Issue Details

• Electron Version:
  • 4.0.4
• Operating System:
  • Ubuntu 18.10 x64

Expected Behavior

Observed in Zulip desktop app

1. tray.destroy() api should destroy tray icon in panel
2. show app tray icon option in general setting, it should destroy and create tray icon on toggle

Actual Behavior

Previous tray icon are not destroy on toggle and new icon created i.e tray.destroy API is not working

To Reproduce

$ git clone https://github.com/zulip/zulip-electron
$ cd zulip-electron
$ npm install
$ npm start

you can find code in zulip-electron/app/renderer/js/tray.js

function toggleTray() {
	let state;
	if (window.tray) {
		state = false;
		window.tray.destroy();
		if (window.tray.isDestroyed()) {
			window.tray = null;
		}
		ConfigUtil.setConfigItem('trayIcon', false);
	} else {
		state = true;
		createTray();
		if (process.platform === 'linux' || process.platform === 'win32') {
			renderNativeImage(unread).then(image => {
				window.tray.setImage(image);
				window.tray.setToolTip(unread + ' unread messages');
			});
		}
		ConfigUtil.setConfigItem('trayIcon', true);
	}
	const selector = 'webview:not([class*=disabled])';
	const webview = document.querySelector(selector);
	const webContents = webview.getWebContents();
	webContents.send('toggletray', state);
}

Screenshots