Dataverse port for previewers

[Dragonking3x]

After adding previewers, they try to look for port 8080.
We can't use port 8080 currently, because another application uses that port.

In docker-compose, there is an option to set the port to "8081:8080", and Dataverse itself works fine with it.
We tried to change the environment setting "socket_port" to 8081, but that doesn't change the port of the previewers.

[Dragonking3x]

I found the environment to fix that problem.

environment:
  - "baseurlstring=${DV_HOSTNAME}\\:8081" # the "\\" are important, because without them the ":" will be cut away 
  -  "dataverse_siteUrl=http://${DV_HOSTNAME}:8081"

We use ${DV_HOSTNAME}, because we use the Ubuntu environment name, but you replace it with "localhost" for testing, the server IP, or the server Domain.
Example:

environment:
  - "baseurlstring=localhost\\:8081"
  -  "dataverse_siteUrl=http://localhost:8081"