Pass URLs not covered by SiteConfiguration

[ohader]

Subject URL: https://example.org/special/documents

Scenario #1:

• SiteConfiguration base is https://example.org/cms/
• Real directory exists in file-system for https://example.org/special/
  → subject URL should not be changed (or result in exception)

Scenario #2:

• SiteConfiguration base is https://example.org/
• Real directory exists in file-system for https://example.org/special/
  → subject URL should not be changed (or result in exception)