Removed private configuration endpoint

refs https://github.com/TryGhost/Ghost/issues/8859

- We don't need the config option for Unsplash anymore
- The private endpoint (/configuration/private) was introduced for Unsplash

core/server/api/configuration.js

@@ -14,14 +14,6 @@ function fetchAvailableTimezones() {
     return timezones;
 }
 
-function fetchPrivateConfig() {
-    var unsplashConfig = config.get('unsplash') || {};
-
-    return {
-        unsplashAPI: unsplashConfig
-    };
-}
-
 function getAboutConfig() {
     return {
         version: ghostVersion.full,
@@ -81,11 +73,6 @@ configuration = {
             return Promise.resolve({configuration: [fetchAvailableTimezones()]});
         }
 
-        // Private configuration config for API keys used by the client
-        if (options.key === 'private') {
-            return Promise.resolve({configuration: [fetchPrivateConfig()]});
-        }
-
         return Promise.resolve({configuration: []});
     }
 };

core/test/integration/api/api_configuration_spec.js

@@ -71,21 +71,4 @@ describe('Configuration API', function () {
             done();
         }).catch(done);
     });
-
-    it('can read private config and get all expected properties', function (done) {
-        ConfigurationAPI.read({key: 'private'}).then(function (response) {
-            var props;
-
-            should.exist(response);
-            should.exist(response.configuration);
-            response.configuration.should.be.an.Array().with.lengthOf(1);
-            props = response.configuration[0];
-
-            // property is set, but value not available, because settings API was not called yet
-            props.should.have.property('unsplashAPI').which.is.an.Object();
-            props.unsplashAPI.should.be.empty();
-
-            done();
-        }).catch(done);
-    });
 });