ovirt-image-uploader: using API SDK insecure parameter

Correctly mapping command line insecure parameter to
API SDK insecure parameter.

Change-Id: I384e4749044bc2a7027cb550d6985bd1f741c9e0
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1102226
Signed-off-by: Simone Tiraboschi <stirabos@redhat.com>