patch 8.1.2421: test88 is old style

Problem:    Test88 is old style.
Solution:   Turn into a new style test. (Yegappan Lakshmanan, closes #5347)
diff --git a/src/testdir/test_python2.vim b/src/testdir/test_python2.vim
index de5b0c9..5cee7a7 100644
--- a/src/testdir/test_python2.vim
+++ b/src/testdir/test_python2.vim
@@ -1,5 +1,5 @@
 " Test for python 2 commands.
-" TODO: move tests from test87.in here.
+" TODO: move tests from test86.in here.
 
 source check.vim
 CheckFeature python