Update Dockerfile

[wangerry]

add default expose port

Description

Add EXPOSE into Dockerfile

Related Issue

RestyaPlatform#4233

Motivation and Context

let traefik detect default port to communicate, and it's recommanded to do.

How Has This Been Tested?

start up a container and docker ps will show it in ports column

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.