Log Message:
mikutter: update to 3.9.0.

Upstream changes (including 3.9.0-alpha ones):

New features of mikutter 3.9

* Mastodon plugin
* Support for UI scaling
* World account can be assigned to shortcut key
* Reorder World accounts
* Non-PNG image support for Skin
* Generic Model viewer
* Quick Step
* PulseAudio
* Reorgenize gem dependencies
* and more..