Make EC2 compatible with current AWS CLI.

Nova listens for EC2 calls now at the URL without path -
http://some.server.com:8773/
I was made in review -
https://review.openstack.org/#/c/152496/

So I suggest to change EC2 urls in keystone catalog.

Change-Id: Ia2975ce0f6a30eed6016733e12c98b5f97648307
Closes-Bug: 1417555
diff --git a/lib/tempest b/lib/tempest
index 86f30b4..9058fa6 100644
--- a/lib/tempest
+++ b/lib/tempest
@@ -359,7 +359,7 @@
     iniset $TEMPEST_CONFIG network-feature-enabled api_extensions $network_api_extensions
 
     # boto
-    iniset $TEMPEST_CONFIG boto ec2_url "$EC2_SERVICE_PROTOCOL://$SERVICE_HOST:8773/services/Cloud"
+    iniset $TEMPEST_CONFIG boto ec2_url "$EC2_SERVICE_PROTOCOL://$SERVICE_HOST:8773/"
     iniset $TEMPEST_CONFIG boto s3_url "http://$SERVICE_HOST:${S3_SERVICE_PORT:-3333}"
     iniset $TEMPEST_CONFIG boto s3_materials_path "$BOTO_MATERIALS_PATH"
     iniset $TEMPEST_CONFIG boto ari_manifest cirros-${CIRROS_VERSION}-${CIRROS_ARCH}-initrd.manifest.xml