patch 8.2.1059: crash when using :tabonly in an autocommand

Problem:    Crash when using :tabonly in an autocommand. (Yegappan Lakshmanan)
Solution:   Do not allow the autocommand window to be closed.
diff --git a/src/window.c b/src/window.c
index 095eabe..e2adc0c 100644
--- a/src/window.c
+++ b/src/window.c
@@ -2461,7 +2461,7 @@
 	return FAIL; // window is already being closed
     if (win_unlisted(win))
     {
-	emsg(_("E813: Cannot close autocmd or popup window"));
+	emsg(_(e_autocmd_close));
 	return FAIL;
     }
     if ((firstwin == aucmd_win || lastwin == aucmd_win) && one_window())