patch 7.4.1424
Problem:    Not using --not-a-term when running tests on MS-Windows.
Solution:   Use NO_PLUGIN. (Christian Brabandt)
diff --git a/src/testdir/Make_dos.mak b/src/testdir/Make_dos.mak
index bfd624c..66cf12f 100644
--- a/src/testdir/Make_dos.mak
+++ b/src/testdir/Make_dos.mak
@@ -114,4 +114,4 @@
 newtests: $(NEW_TESTS)
 
 .vim.res:
-	$(VIMPROG) -u NONE -U NONE -S runtest.vim $*.vim
+	$(VIMPROG) -u NONE $(NO_PLUGIN) -S runtest.vim $*.vim