Fix Scrutinizer issues in mod [_well_know -> contactgroup]

- Remove unused variables and parameter
- Updated function documentation
- Fix formatting
- Add back uninitialized variables
- Simplify nested conditions

src/App.php

@@ -60,6 +60,7 @@ class App {
 	public $timezone;
 	public $interactive = true;
 	public $plugins;
+	public $plugins_admin = array();
 	public $apps = array();
 	public $identities;
 	public $is_mobile = false;