Cleanup dependencies for glance-base

Rely on packagers for managing dependencies.

openstack-glance RPM [1] and glance deb [2] already pull the required
packages.

[1] https://github.com/openstack-packages/glance/blob/rpm-master/openstack-glance.spec
[2] http://ubuntu-cloud.archive.canonical.com/ubuntu/dists/trusty-updates/liberty/main/binary-amd64/Packages

TrivialFix

Change-Id: I8707805db136af77a53372cafd5dcfdffb1f317e

docker/glance/glance-base/Dockerfile.j2

@@ -6,9 +6,6 @@ MAINTAINER {{ maintainer }}
 
 RUN yum -y install \
         openstack-glance \
-        python-oslo-i18n \
-        python-castellan \
-        python-cryptography \
         python-rbd \
         python-rados \
     && yum clean all \
@@ -18,9 +15,6 @@ RUN yum -y install \
 
 RUN apt-get install -y --no-install-recommends \
         glance \
-        python-oslo-i18n \
-        python-castellan \
-        python-cryptography \
         python-rbd \
         python-rados \
     && apt-get clean \