Fix issue with LDAP backend returning bytes instead of string
Fix issue with LDAP backend returning bytes instead of string

When connecting to some LDAP server software, the ldap client returns
bytes instances instead of the expected strings. This can result in
either being transparently converted to strings, when the data is
inserted via sqlalchemy into the database, or could be used as
input to other functions, and/or cached, which causes unexpected
results.

Closes-Bug: #1952458
Resolves: rhbz#1964872
Change-Id: I77148641715efe09e3adc2e9432e66e50fb444b4

mahak/keystone,openstack/keystone,mahak/keystone,openstack/keystone,mahak/keystone,openstack/keystone