Handle no scheduled alarm case

ui/src/lib/alarmsingle.js

@@ -65,7 +65,11 @@ export async function getAlarmSingle(aid) {
 export async function getNextAlarm() {
   const res = await fetch(`api/alarms/next`, {headers: {'Accept': 'application/json'}})
   if (res.status == 200) {
-    return new Date(await res.json());
+    const data = await res.json();
+    if (data)
+      return new Date(data);
+    else
+      return data;
   } else {
     throw new Error((await res.json()).errmsg);
   }

ui/src/routes/+page.svelte

@@ -69,7 +69,10 @@
                 <span class="visually-hidden">Loading...</span>
             </div>
         {:then nextalarm}
-            Prochain réveil&nbsp;:
+            {#if nextalarm === null}
+                <Icon name="x-octagon" /> Pas de prochain réveil programmé
+            {:else}
+                <Icon name="alarm-fill" /> Prochain réveil&nbsp;:
                 {#if nextalarm.getDay() == new Date().getDay() && nextalarm.getMonth() == new Date().getMonth() && nextalarm.getFullYear() == new Date().getFullYear()}
                     aujourd'hui à
                     <DateFormat date={nextalarm} timeStyle="long" />
@@ -87,6 +90,7 @@
                 {:else}
                     <DateFormat date={nextalarm} dateStyle="short" timeStyle="long" />
                 {/if}
+            {/if}
         {/await}
     </div>
     {#await isActiveP then isActive}