Mouse scroll in terminal started to switch tabs: How to switch this off?

With a recent update (I am at guake version 3.9.1.dev0 (according to `guake --version`) from [Arch Linux](https://archlinux.org/packages/community/any/guake/)) when I use mouse wheel on a guake terminal window, guake changes tabs (as well as forwarding the scroll to the currently opened terminal, which changes quickly while scrolling).

In the settings of guake (Right click -> "Preferences"), I don't see that I have mouse scroll assigned to any action, and especially under "Keyboard shortcuts", "Go to previos tab" and "Go to next tab" are assigned to ``+`` and ``+``, respectively.

How can I switch off that mouse scroll switches tabs, so that I can use it to scroll within the terminal window without any interference?

I also don't know where guake stores it's settings; a `find .[a-zA-Z]* | grep guake` in my home directory did only reveal the session storage `.config/guake/session.json`. Otherwise I would have posted my quake configuration file.

Regards!