patch 8.2.4010: error messages are spread out

Problem:    Error messages are spread out.
Solution:   Move more error messages to errors.h.
diff --git a/src/window.c b/src/window.c
index 1d09781..4a17c62 100644
--- a/src/window.c
+++ b/src/window.c
@@ -2501,7 +2501,7 @@
     }
     if ((firstwin == aucmd_win || lastwin == aucmd_win) && one_window())
     {
-	emsg(_("E814: Cannot close window, only autocmd window would remain"));
+	emsg(_(e_cannot_close_window_only_autocmd_window_would_remain));
 	return FAIL;
     }