Ctrl + Q doesn't work if you use a mouse button as Q keybind.

What I expected to happen was...:
Drop a stack of items with ctrl + "Button 4" when I am into my inventory in creative or survival gamemode

What actually happened was...:
It only works if the keybind is a keyboard key. It doesn't work for mouse buttons

Steps to Reproduce:
1. Change your "selected drop item" keybind to any mouse button except left and right click, for example "scroll up", "scroll down", "middle button", "button 4", etc.
2. Have any stackable item on your inventory or hotbar
3. Open your inventory and try Ctrl + (the new mouse key) to drop more than one item