Make Poketab icon visible even when single tab is opened

[inside-hakumai]

This plugin is very cool and thank you for your great job.
I love Poketab function especially.

However, Poketab icon is visible only when multiple tabs are opened.
How about make Poketab icon visible even when single tab is opened?

Preview

I have already implemented this change in my fork of this repository.
If this change is acceptable, can I create a new pull request for it?

[klaudiosinani]

PR welcome : )