Fix empty orders in getSortedOrders

gather/src/api.js

@@ -31,6 +31,10 @@ class Api {
 
   async getSortedOrders (url) {
     const orders = await this.getOrders(url)
+    if (orders.length === 0) {
+      return []
+    }
+
     return orders.sort(function (a, b) {
       return a.platinum - b.platinum
     })