fix 开业营运方案筹备人为null

coolstore-partner-model/src/main/java/com/cool/store/request/OpeningOperationPlanRequest.java

@@ -53,6 +53,8 @@ public class OpeningOperationPlanRequest {
         openingOperationPlanDO.setActivityThemeUrl( this.activityThemeUrl);
         if (CollectionUtils.isNotEmpty(this.preparationUserIds)) {
             openingOperationPlanDO.setPreparationUserIds(String.join(",", this.preparationUserIds));
+        }else if (this.preparationUserIds.isEmpty()){
+            openingOperationPlanDO.setPreparationUserIds("");
         }
         openingOperationPlanDO.setActivityTheme(this.activityTheme);
         openingOperationPlanDO.setRouteCompleted(this.routeCompleted);