多形态资源库删除时，判断是否有流水线使用

ruoyi-modules/management-platform/src/main/java/com/ruoyi/platform/service/impl/WorkflowServiceImpl.java

@@ -351,7 +351,7 @@ public class WorkflowServiceImpl implements WorkflowService {
         Map<String, Object> paramMap = JsonUtils.jsonToMap(inParameters);
         Map<String, Object> model = (Map<String, Object>) paramMap.get("--model_name");
         String value = (String) model.get("value");
-        if (!value.startsWith("{{")) {
+        if (StringUtils.isNotEmpty(value) && !value.startsWith("{{")) {
             Map<String, Object> valueMap = JsonUtils.jsonToMap(value);
             insertAssetWorkFlow(workflowId, workflowName, Long.valueOf((String) valueMap.get("id")), (String) valueMap.get("version"), Constant.Asset_Type_Model);
         }