Make icon optional for ntfy notificaation provider. Add Icon header to ntfy request only, if icon is actually defined.

server/notification-providers/ntfy.js

@@ -7,15 +7,18 @@ class Ntfy extends NotificationProvider {
 
     async send(notification, msg, monitorJSON = null, heartbeatJSON = null) {
         let okMsg = "Sent Successfully.";
-        try {
-            await axios.post(`${notification.ntfyserverurl}`, {
+        var ntfyparams = {
                 "topic": notification.ntfytopic,
                 "message": msg,
                 "priority": notification.ntfyPriority || 4,
                 "title": "Uptime-Kuma",
-                "icon": notification.ntfyIcon || "",
-            });
+        };
+        if (notification.ntfyIcon) {
+        	ntfyparams.icon = notification.ntfyIcon;
+	    }
 
+        try {
+            await axios.post(`${notification.ntfyserverurl}`, ntfyparams);
             return okMsg;
 
         } catch (error) {

src/components/notifications/Ntfy.vue

@@ -19,7 +19,7 @@
 
     <div class="mb-3">
         <label for="ntfy-icon" class="form-label">{{ $t("IconUrl") }}</label>
-        <input id="ntfy-icon" v-model="$parent.notification.ntfyIcon" type="text" class="form-control" required>
+        <input id="ntfy-icon" v-model="$parent.notification.ntfyIcon" type="text" class="form-control">
     </div>
 </template>