Fix: Remove duplicate 'cls' command registration

Author: HossamSaberr

src/main/java/com/mycmd/App.java

@@ -106,7 +106,6 @@ private static void registerCommands(Map<String, Command> commands) {
         commands.put("unalias", new UnaliasCommand());
         commands.put("rename", new RenameCommand());
         commands.put("set", new SetCommand());
-        commands.put("cls", new ClsCommand());
           }
 }