QA: make ipolicy test respect enabled disk templates
QA: make ipolicy test respect enabled disk templates

This makes the 'gnt-cluster modify --ipolicy-*' tests
respect the enabled disk templates on the QA cluster.
If the required disk templates are not enabled, the
test is skipped.

Signed-off-by: Helga Velroyen <2d0126b1ec6f9ec5cbec4a7012aa14faeaef10f5@google.com>
Reviewed-by: Thomas Thrainer <98bdeac947eb8ca18146e9ce7f092788ec242cd1@google.com>

mbakke/ganeti,mbakke/ganeti,grnet/snf-ganeti,apyrgio/ganeti,ganeti/ganeti,dimara/ganeti,andir/ganeti,yiannist/ganeti,andir/ganeti,apyrgio/snf-ganeti,grnet/snf-ganeti,ganeti/ganeti,ganeti-github-testing/ganeti-test-1,ganeti-github-testing/ganeti-test-1,onponomarev/ganeti,yiannist/ganeti,apyrgio/snf-ganeti,mbakke/ganeti,ganeti/ganeti,bitemyapp/ganeti,onponomarev/ganeti,leshchevds/ganeti,apyrgio/ganeti,dimara/ganeti,andir/ganeti,bitemyapp/ganeti,leshchevds/ganeti,leshchevds/ganeti,yiannist/ganeti