Revert "vim-patch:8.1.0822: peeking and flushing output slows down execution"

This reverts commit 0519a75f6e.

src/nvim/edit.c

@@ -7803,7 +7803,7 @@ static bool ins_esc(long *count, int cmdchar, bool nomove)
   // Otherwise remove the mode message.
   if (reg_recording != 0 || restart_edit != NUL) {
     showmode();
-  } else if (p_smd && !skip_showmode()) {
+  } else if (p_smd) {
     MSG("");
   }
   // Exit Insert mode