storage domain detach with force fails

In jsonrpc schema masterSdUUID and masterVersion are marked as optional.
We need to provide default values for both arguments.


Bug-Url: https://bugzilla.redhat.com/1110831
Change-Id: I17058f86448c0019520ea9315da5524c5b3f2b6c
Signed-off-by: pkliczewski <piotr.kliczewski@gmail.com>
Reviewed-on: http://gerrit.ovirt.org/32503
Reviewed-by: Dan Kenigsberg <danken@redhat.com>