tabbing: refresh the edit window in case a previous tab listed names

Commit 36ec76a made the wrong change: after a tab that did not list any
file names on the screen, a refresh /is/ needed, because a previous tab
might have listed things on the screen.  But at the end of the prompt,
it is not necessary to refresh the edit window if things were listed,
because the window will be refreshed anyway after reading in a file.
3 files changed