PreProcess lisArr null验证

push-web/src/main/java/org/diagbot/push/convert/PreProcess.java

@@ -270,6 +270,9 @@ public class PreProcess {
     }
 
     private List<LisDetail> processLis(List<LisDetail> lisArr) {
+        if (lisArr == null) {
+            return new ArrayList<>();
+        }
         if (lisArr.size() == 0) {
             return lisArr;
         }