[Composer] Ctrl+Shift+Backspace deletion cannot be undone
On my laptop, sometimes I want to delete a single word by hitting ctrl+delete, but since the shift key is pretty close I accidentally hit shift at the same time, so shift+ctrl+delete, which deletes the whole line... the problem is that I cannot undo this in Evolution's mail composer, so I may have written a whole paragraph and it's gone forever because my pinkie finger wasn't entirely accurate. This feature is dangerous. Either the ctrl+shift+delete combo should do nothing, or it should be an undoable action.