Can't change keybind on self target.

[Ninjapilot10]

Some items require you to self-target to activate them, the default keybind for this is middle mouse; my middle mouse button is broken, and there's no option to change the keybind, so I just can't use some items. I assume this is just an oversight, but I feel that it's a big enough issue that it should be reported as a bug.