[SSSD] [sssd PR#390][opened] NSS: Add option to disable memcache

[mzidek-rh]

   URL: https://github.com/SSSD/sssd/pull/390
Author: mzidek-rh
 Title: #390: NSS: Add option to disable memcache
Action: opened

PR body:
"""
Added option use_memcache to centrally disable memcache
for all clients without the need to specify SSS_NSS_USE_MEMCACHE=NO
environment variable.

Resolves:
https://pagure.io/SSSD/sssd/issue/3496
"""

To pull the PR as Git branch:
git remote add ghsssd https://github.com/SSSD/sssd
git fetch ghsssd pull/390/head:pr390
git checkout pr390