Simplify database_connection_url

* does not expects dynamic scoping.
* does not uses eval.

Change-Id: I5ba4e5b7ffaabbb3c2bddadf9e53a2875de8b7c0
diff --git a/lib/keystone b/lib/keystone
index 2e2471a..a04d9d5 100644
--- a/lib/keystone
+++ b/lib/keystone
@@ -91,8 +91,6 @@
     fi
 
     # Rewrite stock ``keystone.conf``
-    local dburl
-    database_connection_url dburl keystone
 
     if is_service_enabled ldap; then
         #Set all needed ldap values
@@ -123,7 +121,7 @@
 
     iniset $KEYSTONE_CONF DEFAULT admin_token "$SERVICE_TOKEN"
     iniset $KEYSTONE_CONF signing token_format "$KEYSTONE_TOKEN_FORMAT"
-    iniset $KEYSTONE_CONF sql connection $dburl
+    iniset $KEYSTONE_CONF sql connection `database_connection_url keystone`
     iniset $KEYSTONE_CONF ec2 driver "keystone.contrib.ec2.backends.sql.Ec2"
     sed -e "
         /^pipeline.*ec2_extension crud_/s|ec2_extension crud_extension|ec2_extension s3_extension crud_extension|;