Silence failures to trigger notifications when not available

Recent Chrome versions are dropping out `new Notification` in favor of `ServiceWorkerRegistration.showNotification`.
This makes sure nothing bad happens until we have proper support for Service Workers.

See:
- https://stackoverflow.com/questions/29774836/failed-to-construct-notification-illegal-constructor
- https://stackoverflow.com/questions/31512504/html5-notification-not-working-in-mobile-chrome

client/js/lounge.js

@@ -1031,6 +1031,7 @@ $(function() {
 						body = msg.text.replace(/\x02|\x1D|\x1F|\x16|\x0F|\x03(?:[0-9]{1,2}(?:,[0-9]{1,2})?)?/g, "").trim();
 					}
 
+					try {
 						var notify = new Notification(title, {
 							body: body,
 							icon: "img/logo-64.png",
@@ -1044,6 +1045,10 @@ $(function() {
 						window.setTimeout(function() {
 							notify.close();
 						}, 5 * 1000);
+					} catch (exception) {
+						// `new Notification(...)` is not supported and should be silenced.
+					}
+
 				}
 			}
 		}