add removal todo comment

Author: jjw24

Plugins/Flow.Launcher.Plugin.Shell/Main.cs

@@ -386,6 +386,7 @@ public void Init(PluginInitContext context)
             context.API.RegisterGlobalKeyboardCallback(API_GlobalKeyboardEvent);
             // Since the old Settings class set default value of ShowOnlyMostUsedCMDsNumber to 0 which is a wrong value,
             // we need to fix it here to make sure the default value is 5
+            // todo: remove this code block after release v2.2.0
             if (_settings.ShowOnlyMostUsedCMDsNumber == 0)
             {
                 _settings.ShowOnlyMostUsedCMDsNumber = 5;