Let site (starter or otherwise) set media urls.

[rosiel]

GitHub Issue: in part, addresses #248

• Other Relevant Links (Google Groups discussion, related pull requests,
  Release pull requests, etc.)

What does this Pull Request do?

Doesn't set media urls to have "Standalone URLs". This configuration is part of the starter site / install profile / whatever site you're using. The playbook currently insists on overriding whatever value you have set there in your site, which I think it shouldn't do.

What's new?

• Removed a line that sets the value to be true.
• Does this change require documentation to be updated? Some screenshots might need updating if they show media pages.
• Does this change add any new dependencies? no
• Does this change require any other modifications to be made to the repository
  (i.e. Regeneration activity, etc.)? no
• Could this change impact execution of existing code? no

How should this be tested?

Without this PR:

• install the starter site using "starter_dev"
• once installed, check the config diff using drush cex --diff. You should see that the media URLs have been set to True.

With this PR:

• the drush cex --diff should not include this, because the value wasn't set in a way that contradicts the starter site.

Additional Notes:

Any additional information that you think would be helpful when reviewing this
PR.

Interested parties

Tag (@ mention) interested parties or, if unsure, @Islandora-Devops/committers

[rosiel]

Anyone have the time to check this one out?