patch 8.1.2030: tests fail when build with normal features and terminal

Problem:    Tests fail when build with normal features and terminal.
            (Dominique Pelle)
Solution:   Disable tests that won't work. (closes #4932)
diff --git a/src/testdir/test_popupwin.vim b/src/testdir/test_popupwin.vim
index a338169..feb8ce3 100644
--- a/src/testdir/test_popupwin.vim
+++ b/src/testdir/test_popupwin.vim
@@ -1136,6 +1136,7 @@
 
 func Test_popup_beval()
   CheckScreendump
+  CheckFeature balloon_eval
 
   let lines =<< trim END
 	call setline(1, range(1, 20))