FIX: Allow accessing nested objects within theme settings

FIX: Allow accessing nested objects within theme settings

This is required to access keys within the new theme_uploads object

diff --git a/app/assets/javascripts/discourse/services/theme-settings.js.es6 b/app/assets/javascripts/discourse/services/theme-settings.js.es6
index 5e1e8a8..1ff2300 100644
--- a/app/assets/javascripts/discourse/services/theme-settings.js.es6
+++ b/app/assets/javascripts/discourse/services/theme-settings.js.es6
@@ -12,7 +12,7 @@ export default Ember.Service.extend({
 
   getSetting(themeId, settingsKey) {
     if (this._settings[themeId]) {
-      return this._settings[themeId][settingsKey];
+      return Ember.get(this._settings[themeId], settingsKey);
     }
     return null;
   },

GitHub sha: 3c6176b8