Description of problem:

If I try submit job with duplicate packages defined, server returns Fault. Duplicate was added by accident, however server should not crack up.

Version-Release number of selected component (if applicable):
Version - 0.10.5

How reproducible:
Submit this:
<job>
    <whiteboard></whiteboard>
    <recipeSet>
        <recipe>
            <distroRequires>
                <and>
                    <distro_arch op="=" value="x86_64"/>
                    <distro_name op="=" value="RHEL-6.3"/>
                    <distro_variant op="=" value="Server"/>
                </and>
            </distroRequires>
            <hostRequires/>
            <packages>
                <package name="system-config-kdump"/>
                <package name="system-config-kdump"/>
            </packages>
            <task name="/distribution/install" role="STANDALONE"/>
        </recipe>
    </recipeSet>
</job>



Actual results:
Exception: <Fault 1: '<class \'sqlalchemy.exc.IntegrityError\'>:(IntegrityError) (1062, "Duplicate entry \'730496-103\' for key 1") \'INSERT INTO task_packages_custom_map (recipe_id, package_id) VALUES (%s, %s)\' ((730496L, 103L), (730496L, 103L))'>


Expected results:
Successful submit