[Openstack-stable-maint] [Neutron] Exception for backporting patch 95491

Hi, we'd like to have backported patch [1] and I'd like to ask for an exception because this patch introduces new config option for defining caching backend for metadata agent. By default, the cache is turned off therefore default behavior is not changed. Caching on metadata agent side offloads neutron-server and improves scalability. Thank you Kuba [1] https://review.openstack.org/#/c/95491/