Sentinel dashboard cannot display properly when the spring boot application has a context path

[seedscoder]

Issue Description

Type: bug report or feature request

Describe what happened (or what feature you want)

Describe what you expected to happen

• Sentinel dashboard cannot display properly when the spring boot application has a context path

How to reproduce it (as minimally and precisely as possible)

• application.yml

server:
  port: 9000
  servlet:
    context-path: /sentinel-demo

spring:
  application:
    name: sentinel-demo
  cloud:
    sentinel:
      transport:
        dashboard: localhost:8080

• result
  

• When I delete the context path
  

Tell us your environment

• Spring Cloud Alibaba 2.2.0.RELEASE

Anything else we need to know?

• What do I need to do to display correctly

[cdfive]

Try add filter.url-patterns: /** in application.yml:

spring:
  application:
    name: sentinel-demo
  cloud:
    sentinel:
      transport:
        dashboard: localhost:8080
      filter:
        url-patterns: /**

The Spring Cloud Alibaba 2.2.1.RELEASE has improved this configuration by default.

Refer to #1380、#1343

[seedscoder]

Thank you very much