update pig-visual/pig-sentinel-dashboard/src/main/resources/application.yml.

sentinel服务添加nacos账号密码配置，否则服务无法正常启动
Signed-off-by: Nunreleased <unreleased@qq.com>

pig-visual/pig-sentinel-dashboard/src/main/resources/application.yml

@@ -9,6 +9,8 @@ spring:
     name: @artifactId@
   cloud:
     nacos:
+      username: @nacos.username@
+      password: @nacos.password@
       discovery:
         server-addr: ${NACOS_HOST:pig-register}:${NACOS_PORT:8848}