patch 8.1.0064: typing CTRL-W in a prompt buffer shows mode "-- --"

Problem:    Typing CTRL-W in a prompt buffer shows mode "-- --".
Solution:   Set restart_edit to 'A' and check for it.
diff --git a/src/edit.c b/src/edit.c
index 326a382..3204ec3 100644
--- a/src/edit.c
+++ b/src/edit.c
@@ -1179,7 +1179,7 @@
 		// In a prompt window CTRL-W is used for window commands.
 		// Use Shift-CTRL-W to delete a word.
 		stuffcharReadbuff(Ctrl_W);
-		restart_edit = 'i';
+		restart_edit = 'A';
 		nomove = TRUE;
 		count = 0;
 		goto doESCkey;