allow empty Auth0 credentials

Fixes stuck loading animation (spinner).

app/Application.js

@@ -35,7 +35,9 @@ Ext.define('Rambox.Application', {
 		Ext.Loader.loadScript({url: Ext.util.Format.format("ext/packages/ext-locale/build/ext-locale-{0}.js", localStorage.getItem('locale-auth0') || 'en')});
 
 		// Initialize Auth0
-		Rambox.ux.Auth0.init();
+		if (auth0Cfg.clientID!=='', auth0Cfg.domain!==''){
+			Rambox.ux.Auth0.init();
+		}
 
 		// Set cookies to help Tooltip.io messages segmentation
 		Ext.util.Cookies.set('version', require('electron').remote.app.getVersion());