patch 8.2.1951: test for list and dict fails

Problem:    Test for list and dict fails.
Solution:   Adjust for using an empty list/dict for a null one.
diff --git a/src/testdir/test_python2.vim b/src/testdir/test_python2.vim
index fd8fe70..ba73c12 100644
--- a/src/testdir/test_python2.vim
+++ b/src/testdir/test_python2.vim
@@ -353,12 +353,12 @@
   call AssertException(["py t = vim.eval('[test_null_list()]')"],
         \ 'Vim(python):SystemError: error return without exception set')
 
-  " Try to bind a null List variable
+  " Try to bind a null List variable (works because an empty list is used)
   let cmds =<< trim END
     let l = test_null_list()
     py ll = vim.bindeval('l')
   END
-  call AssertException(cmds, 'Vim(python):SystemError: error return without exception set')
+  call AssertException(cmds, '')
 
   let l = []
   py l = vim.bindeval('l')