This patch was developed in-house.  We need to study Mailman 3 to determine
if the issue is still applicable, then offer it upstream if so.

--- mailman-2.1.18-1/misc/Makefile.in.orig	2014-05-06 09:43:56.000000000 -0700
+++ mailman-2.1.18-1/misc/Makefile.in	2016-08-03 08:26:58.188204114 -0700
@@ -88,7 +88,7 @@
 	    $(INSTALL) -m $(FILEMODE) paths.py $$dir; \
 	done
 	$(INSTALL) -m $(EXEMODE) mailman $(DESTDIR)$(SCRIPTSDIR)
-	$(INSTALL) -m $(FILEMODE) sitelist.cfg $(DESTDIR)$(DATADIR)
+	$(INSTALL) -m $(FILEMODE) $(srcdir)/sitelist.cfg $(DESTDIR)$(DATADIR)
 
 install-packages:
 	if [ -z "$(EMAILPKG)" -a -d $(DESTDIR)$(PYTHONLIBDIR)/email ] ; \