Fix make uninstall

Make uninstall currently fails with the following message:

rmdir /etc/sasl2/
rmdir: failed to remove `/etc/sasl2/': Directory not empty

That's fine (correct in fact) so force the command to return success
with || :

daemon/Makefile.am

@@ -351,7 +351,7 @@ install-data-sasl:
 
 uninstall-data-sasl:
 	rm -f $(DESTDIR)$(sysconfdir)/sasl2/libvirt.conf
-	rmdir $(DESTDIR)$(sysconfdir)/sasl2/
+	rmdir $(DESTDIR)$(sysconfdir)/sasl2/ || :
 else
 install-data-sasl:
 uninstall-data-sasl: