Description of problem:
Import disk as template in v3 fails with http 500

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


How reproducible:
100%

Steps to Reproduce:
1.connect glance
2.try to import image as template with v3:
/ovirt-engine/api/storagedomains/b9f6c2a0-41de-4afb-a9aa-6c19fbbd4d4d/images/d7eafdaa-f5fd-48fa-991d-1c51b15a243d/import

body:
<action>
    <async>false</async>
    <grace_period>
        <expiry>10</expiry>
    </grace_period>
    <storage_domain>
        <name>nfs_2</name>
    </storage_domain>
    <cluster>
        <name>golden_env_mixed_1</name>
    </cluster>
    <template>
        <name>golden_mixed_virtio_template</name>
    </template>
    <import_as_template>true</import_as_template>
    <disk>
        <name>golden_mixed_virtio_template</name>
    </disk>
</action>
3.

Actual results:
HTTP 500

Expected results:
HTTP 200

Additional info:
It is working with v4