In patch[1], the change didn't completely fix the issue
that can't open NGT creating widget if django didn't upgrade
to the lastest version 1.11.
This patch fixes the issue by rewriting the method "build_attrs".
[1] https://review.openstack.org/#/c/489576/
Change-Id: I748c71fd26d3abaf4a059db3c2224589284131c6