Fix potential crash

apps/widbaroalarm/ChangeLog

@@ -1,2 +1,3 @@
 0.01: Initial version
 0.02: Do not warn multiple times for the same exceedance
+0.03: Fix crash

apps/widbaroalarm/metadata.json

@@ -2,7 +2,7 @@
   "id": "widbaroalarm",
   "name": "Barometer Alarm Widget",
   "shortName": "Barometer Alarm",
-  "version": "0.02",
+  "version": "0.03",
   "description": "A widget that can alarm on when the pressure reaches defined thresholds.",
   "icon": "widget.png",
   "type": "widget",

apps/widbaroalarm/widget.js

@@ -104,7 +104,7 @@
       saveSetting("lastHighWarningTs", 0);
     }
 
-    if (!alreadyWarned) {
+    if (history3.length > 0 && !alreadyWarned) {
       // 3h change detection
       const drop3halarm = setting("drop3halarm");
       const raise3halarm = setting("raise3halarm");