This reverts commit 6d00fdf8c8e4003a89d622590265d80356a7a95f.
As unfortunate as it is, this workaround was a hack and doesn't take
into account prompts like spaceship which don't use $editor_info but
rely on $KEYMAP directly. We'll need to find a more consistent solution
to fix this.
This was a change in zsh 5.4.1 where prompt_sp is now reset on calls to
prompt, unlike previous behavior where it was set by default. This
restores the previous default behavior.
Refs #1423, but is not a complete fix because we need to wait for
external prompts to update as well.
Kaleb Elwert