qemuxml2argvdata: Drop useless spaces at the beginning of lines

qemuxml2argvdata: Drop useless spaces at the beginning of lines

There are three test XMLs that have useless spaces at the
beginning of each line. I intend to add these to qemuxml2xmltest
and make xmlout a symlink to the original XML. In order to do
that the XMLs must look better than they do now.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>