patch 8.1.2063: some tests fail when +balloon_eval_term is missing

Problem:    Some tests fail when +balloon_eval_term is missing but
            _balloon_eval is present. (Dominique Pelle)
Solution:   Check the right feature in the test. (closes #4962)
diff --git a/src/testdir/test_popupwin.vim b/src/testdir/test_popupwin.vim
index 6f7cae6..11e554f 100644
--- a/src/testdir/test_popupwin.vim
+++ b/src/testdir/test_popupwin.vim
@@ -1137,7 +1137,7 @@
 
 func Test_popup_beval()
   CheckScreendump
-  CheckFeature balloon_eval
+  CheckFeature balloon_eval_term
 
   let lines =<< trim END
 	call setline(1, range(1, 20))