๊Update FCM example

Author: mobizt

examples/Messaging/WebClient/fcm.html

@@ -15,7 +15,7 @@
             width: 100%;
             max-height: 8rem;
             min-height: 3rem;
-            overflow-y: scroll;
+            overflow-y: auto;
             padding: 10px;
             background-color: #0000001a;
             border: solid rgba(0, 0, 0, 0.15);