Resetting key bindings to their defaults is not possible in-game

A few days ago, I thought it would be fun to try playing the game using only a controller, so I rebound a lot of keys to gamepad buttons, and now that I've had my fun, I found out quickly that you can't reset the bindings back to their defaults.
Especially the fact that you can't assign the Ctrl key (Not LCtrl or RCtrl) to a keybind to have settings open using any control key...