[UI] null pointer exception (#6325)

dolphinscheduler-ui/src/js/conf/home/pages/security/pages/warningInstance/_source/createWarningInstance.vue

@@ -127,6 +127,10 @@
             if (item.title.indexOf('$t') !== -1) {
               item.title = this.$t(item.field)
             }
+            // fix null pointer exception
+            if (!item.props) {
+              item.props = {}
+            }
           })
         }).catch(e => {
           this.$message.error(e.msg || '')