Change the version special case for alembic
Change the version special case for alembic

alembic has changed the way its version is reflected in its tarball
since we stopped building it, in order to start building it again we
need to adjust o the alembic special case accordingly.

Change-Id: I23459ed5755290a9cb3006998681858198f88766

openstack-packages/delorean,openstack-packages/delorean,openstack-packages/DLRN,openstack-packages/DLRN