patch 8.1.1298: invalid argument test fails without X clipboard

Problem:    Invalid argument test fails without X clipboard.
Solution:   Test -display only with the +xterm_clipboard feature.
diff --git a/src/testdir/test_startup.vim b/src/testdir/test_startup.vim
index 61c5082..8f494a8 100644
--- a/src/testdir/test_startup.vim
+++ b/src/testdir/test_startup.vim
@@ -430,7 +430,7 @@
     call assert_equal('More info with: "vim -h"',            out[2])
   endif
 
-  if has('clipboard')
+  if has('xterm_clipboard')
     let out = split(system(GetVimCommand() .. ' -display'), "\n")
     call assert_equal(1, v:shell_error)
     call assert_match('^VIM - Vi IMproved .* (.*)$',         out[0])