Docs: Revise docker run command

[bankierubybank]

This PR revises docker run command as it mapping wrong port (8888) as this image expose port 8080.

Refer to Dockerfile, this image expose port 8080:

IWA-Java/Dockerfile

Line 9 in 2998449

EXPOSE 8080

In readme file, docker run mapping port 8888 instead of 8080:

IWA-Java/README.md

Line 68 in 2998449

docker run -d -p 8888:8888 iwa

The correct command to run this docker image is:
docker run -d -p 8888:8080 iwa

Noted that port 8888 can be changed to any port that not used by Docker host.

[rohitbaryha1]

thanks for the change