patch 8.2.4611: typos in tests; one lua line not covered by test

Problem:    Typos in tests; one lua line not covered by test.
Solution:   Fix typos. Add test case. (Dominique Pellé, closes #9994)
diff --git a/src/testdir/test_breakindent.vim b/src/testdir/test_breakindent.vim
index d60b2f4..9b6106d 100644
--- a/src/testdir/test_breakindent.vim
+++ b/src/testdir/test_breakindent.vim
@@ -731,7 +731,7 @@
 	\ "shall make no law   ",
 	\ ]
   call s:compare_lines(expect, lines)
-  " set mininum indent
+  " set minimum indent
   setl briopt=min:5
   redraw!
   let lines = s:screen_lines2(1, 6, 20)