fix: disabling a setting with subsettings should be stored

this was caused because of the way we checked for a settings key to be available. If the setting would return a falsy value, this would cause the default value to be stored.

fixes #85

app/core/settings-entry.js

@@ -21,28 +21,28 @@ export class SettingsEntry {
   addSetting(label, key, defaultValue, cb) {
     const settings = Database.getJson(`settings:${this.id}`, {});
 
-    settings[key] = settings[key] ? settings[key] : defaultValue;
+    settings[key] = key in settings ? settings[key] : defaultValue;
     Database.setJson(`settings:${this.id}`, settings);
 
     this.settings.push({
       label,
       key,
-      value: settings[key] ? settings[key] : defaultValue,
+      value: key in settings ? settings[key] : defaultValue,
       callback: cb,
       subsettings: [],
     });
   }
 
   addSettingUnder(underKey, label, key, defaultValue, cb) {
     const settings = Database.getJson(`settings:${this.id}`, {});
-    settings[key] = settings[key] ? settings[key] : defaultValue;
+    settings[key] = key in settings ? settings[key] : defaultValue;
     Database.setJson(`settings:${this.id}`, settings);
 
     const setting = this.settings.find(s => s.key === underKey);
     setting.subsettings.push({
       label,
       key,
-      value: settings[key] ? settings[key] : defaultValue,
+      value: key in settings ? settings[key] : defaultValue,
       callback: cb,
     });
   }