When a key triggers a commit while no candidate is selected, the cursor should **always** be corrected leftwards

[mike-fabian]

Currently, when committing while no candidate is selected, the cursor is corrected lefwards only

• if key.shift and key.val in self._keys_which_select_with_shift:

or:

• elif (key.val in (IBus.KEY_Left, IBus.KEY_KP_Left, IBus.KEY_BackSpace)):

First of all, no distinction needs to be made between these two cases, the cursor can be adjusted leftwards to where the caret was in both these cases. So first of all, the code can be simplified.

Second, the cursor can, and should be adjusted leftwards even when other keys triggered the commit.

No matter what key triggered a commit (while no candidate was selected!), the cursor should end up where the caret was when the commit was triggered.