patch 9.0.1386: options test fails with some window width

Problem:    Options test fails with some window width.
Solution:   Adjust what text the test checks with. (closes #12111)
diff --git a/src/testdir/test_options.vim b/src/testdir/test_options.vim
index b3b90d1..e1b5622 100644
--- a/src/testdir/test_options.vim
+++ b/src/testdir/test_options.vim
@@ -1058,8 +1058,9 @@
   exe "normal \<C-c>"
   call assert_equal('Beep!', Screenline(&lines))
   call assert_equal('line    4:', Screenline(&lines - 1))
-  " only match the final colon in the line that shows the source
-  call assert_match(':$', Screenline(&lines - 2))
+  " also check a line above, with a certain window width the colon is there
+  call assert_match('Test_debug_option:$',
+        \ Screenline(&lines - 3) .. Screenline(&lines - 2))
   set debug&
 endfunc