fix issue with burndown charts when first day has acq items.

frontend/src/lib/components/common/BurndownChart.svelte

@@ -73,7 +73,7 @@
       const currentX = new Date(date+"T00:00:00Z").getTime();
       const prevX = currentX - 86400000;
 
-      if (dataMap[prevX] == null) {
+      if (dataMap[prevX] == null && prevX > fromTime) {
         dataMap[prevX] = last;
       }
       dataMap[currentX] = value;