spec: fix for fc29 compatibility
spec: fix for fc29 compatibility

In recent fedora either python2 or python3 must be
explicitly used.

Change-Id: Ia3d2c56aba7151d602cec255208793f5300b4bba
Signed-off-by: Sandro Bonazzola <fcb014d63786651910af5db2ecc5316c668188ef@redhat.com>

oVirt/ovirt-scheduler-proxy,oVirt/ovirt-scheduler-proxy,oVirt/ovirt-scheduler-proxy