There is for sure a way to remove that if you add your own custom nav bar, (as in adding it as a widget) but I’m not sure about the default one. Sorry I couldn’t be more help, but if nothing else that is an option!
Comic -> Config -> Navigation [tab]
Enable the comment link in the comic navigation? [x]
When this is enabled, a link will appear in the navigation that lets you go to the comments section of the current post, it also shows how many comments there currently are.
… uncheck that box, click save.