Fixes bug 1146794
Ensure the URLs configured for the ceilometer endpoint in the keystone
service catalog do not contain a trailing forward slash.
Otherwise, this leads to an extra forward slash in the URL paths
constructed by the ceilometer client, which in turn is problematic
for the v2 API.
Change-Id: I7d457efc6e01e4e955388f52a4907524052f0173