patch 8.1.0811: too many #ifdefs

Problem:    Too many #ifdefs.
Solution:   Graduate FEAT_MBYTE, the final chapter.
diff --git a/src/testdir/test_alot_utf8.vim b/src/testdir/test_alot_utf8.vim
index 648d806..be0bd01 100644
--- a/src/testdir/test_alot_utf8.vim
+++ b/src/testdir/test_alot_utf8.vim
@@ -2,8 +2,7 @@
 " This makes testing go faster, since Vim doesn't need to restart.
 
 " These tests use utf8 'encoding'.  Setting 'encoding' is already done in
-" runtest.vim.  Checking for the multi_byte feature is in the individual
-" files, so that they can be run by themselves.
+" runtest.vim.
 
 source test_charsearch_utf8.vim
 source test_expr_utf8.vim