修复小错误，避免启动失败

ruoyi-demo/src/main/java/com/ruoyi/demo/controller/PlanController.java

@@ -100,7 +100,7 @@ public class PlanController {
         return R.fail("广告添加失败");
     }
     // 删除广告推送计划
-    @DeleteMapping("/{planId")
+    @DeleteMapping("/{planId}")
     public R deletePlan(@PathVariable String planId){
         int i = planService.deletePlan(planId);
         if (i == 1)