Ensure sql assignment driver is set
diff --git a/keystone/files/kilo/keystone.conf.Debian b/keystone/files/kilo/keystone.conf.Debian
index c9e6320..e546e18 100644
--- a/keystone/files/kilo/keystone.conf.Debian
+++ b/keystone/files/kilo/keystone.conf.Debian
@@ -273,6 +273,8 @@
#driver = <None>
{%- if server.get("assignment", {}).get("backend", "sql") == "ldap" %}
driver = keystone.assignment.backends.ldap.Assignment
+{%- else %}
+driver = keystone.assignment.backends.sql.Assignment
{%- endif %}
diff --git a/keystone/files/liberty/keystone.conf.Debian b/keystone/files/liberty/keystone.conf.Debian
index b706f95..8599fb9 100644
--- a/keystone/files/liberty/keystone.conf.Debian
+++ b/keystone/files/liberty/keystone.conf.Debian
@@ -286,6 +286,8 @@
#driver = <None>
{%- if server.get("assignment", {}).get("backend", "sql") == "ldap" %}
driver = ldap
+{%- else %}
+driver = sql
{%- endif %}