preferences page: Reflect changes in the preference page. (#362)

This updated the setting page if the sidebar was toggled using a shortcut.
This also updates the setting page if the tray was toggled using menu.

Fixes: #304.

app/renderer/js/main.js

@@ -262,6 +262,13 @@ class ServerManagerView {
 			tabs: this.tabs,
 			activeTabIndex: this.activeTabIndex
 		});
+
+		ipcRenderer.on('toggle-sidebar', (event, state) => {
+			const selector = 'webview:not([class*=disabled])';
+			const webview = document.querySelector(selector);
+			const webContents = webview.getWebContents();
+			webContents.send('toggle-sidebar', state);
+		});
 	}
 
 	destroyTab(name, index) {