patch 9.1.1496: terminal: still not highlighting empty cells correctly

Problem:  terminal: still not highlighting empty cells correctly
          (Yousef Mohammed, after v9.1.1489)
Solution: Use vcol instead of col

closes: #17632

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/test_terminal3.vim b/src/testdir/test_terminal3.vim
index 9aa9049..7a2ecdb 100644
--- a/src/testdir/test_terminal3.vim
+++ b/src/testdir/test_terminal3.vim
@@ -1032,6 +1032,10 @@
   call term_wait(buf)
   call term_sendkeys(buf, "V2k")
   call VerifyScreenDump(buf, 'Test_terminal_empty_listchars', {})
+  call term_sendkeys(buf, "\<esc>")
+  call term_sendkeys(buf, ":set nu\<cr>")
+  call term_sendkeys(buf, "ggV2j")
+  call VerifyScreenDump(buf, 'Test_terminal_empty_listchars2', {})
 
   call StopVimInTerminal(buf)
 endfunc