patch 8.1.1951: mouse double click test is a bit flaky
Problem: Mouse double click test is a bit flaky.
Solution: Add to list of flaky tests. Update a couple of comments.
diff --git a/src/testdir/test_substitute.vim b/src/testdir/test_substitute.vim
index 344bb68..a263fb6 100644
--- a/src/testdir/test_substitute.vim
+++ b/src/testdir/test_substitute.vim
@@ -504,7 +504,7 @@
call Run_SubCmd_Tests(tests)
endfunc
-" Test for submatch() on :substitue.
+" Test for submatch() on :substitute.
func Test_sub_cmd_4()
set magic&
set cpo&