Fix ports used by docker

[pe1uca]

• Update host docker port to 1236 as described in the documentation
• Update container docker port to 1236 as used in the nginx.conf file
• Removed exposed port 8536 from dockerfile as it's already handled by nginx.

[Nutomic]

Maybe it would be better to use port 80 for all containers? Its logical because its http, and means theres no need to lookup the port of each one separately. Of course this would require changes to docs and existing installations.

[dessalines]

This is correct, we should've never merged the 80:80 one.

@Nutomic Its a test docker setup, so its best not to use 80 on our dev machines, which is nearly always going to have conflicts.