apt-get install foo/trusty selects version from trusty-updates

[Michael Vogt]

When using the release modfiers on the apt commandline specifying the release does not always work, e.g.:
"""
$ apt-get install --reinstall webapp-container/trusty -s)
...
Selected version '0.23+14.04.20140416-0ubuntu1' (Ubuntu:14.04/trusty-updates [amd64]) for 'webapp-container'
"""

The reason is that apt-get foo/release matches for both "Suite" and "Codename" in the Release file. The trusty-updates
Release file looks like this:
"""
 Suite: trusty-updates
 Codename: trusty
"""
So apt matches the suite first, then the codename and takes the match.

Previously it would only match on "Suite", but commit efc487fb changed this behavior (some time ago). Attached is a testcase to illustrate the issue.