patch 8.2.3637: typos in test files

Problem:    Typos in test files.
Solution:   Correct the typos. (Dominique Pellé, closes #9175)
diff --git a/src/testdir/test_options.vim b/src/testdir/test_options.vim
index 3e9bbf4..585b199 100644
--- a/src/testdir/test_options.vim
+++ b/src/testdir/test_options.vim
@@ -1154,7 +1154,7 @@
   set cmdheight&
 endfunc
 
-" To specify a control character as a option value, '^' can be used
+" To specify a control character as an option value, '^' can be used
 func Test_opt_control_char()
   set wildchar=^v
   call assert_equal("\<C-V>", nr2char(&wildchar))