Revert "Move default Keystone API version to v3"

It seems like the fallout from this was not well sorted.
A lot of things aren't working, and there is still vestigial
v2 bits left behind.

This should have come with a much greater warning and some
spot checking of additional services working with this.

This reverts commit b162a1d58cdecfb32847b59bd341e06c26efb1ed.

Change-Id: Ia792b23119c00089542ba08879dca1c29dc80945
diff --git a/lib/glance b/lib/glance
index bf0643b..0431bba 100644
--- a/lib/glance
+++ b/lib/glance
@@ -205,7 +205,7 @@
     iniset $GLANCE_CACHE_CONF DEFAULT use_syslog $SYSLOG
     iniset $GLANCE_CACHE_CONF DEFAULT image_cache_dir $GLANCE_CACHE_DIR/
     iniuncomment $GLANCE_CACHE_CONF DEFAULT auth_url
-    iniset $GLANCE_CACHE_CONF DEFAULT auth_url $KEYSTONE_AUTH_URI/v3
+    iniset $GLANCE_CACHE_CONF DEFAULT auth_url $KEYSTONE_AUTH_URI/v2.0
     iniuncomment $GLANCE_CACHE_CONF DEFAULT auth_tenant_name
     iniset $GLANCE_CACHE_CONF DEFAULT admin_tenant_name $SERVICE_TENANT_NAME
     iniuncomment $GLANCE_CACHE_CONF DEFAULT auth_user