quick fix to Fedora - remove a no in compose pkg from ks

as migrate.after_extensive_io.iscsi needs scsi-target-utils
and actually Fedora didn't include it in the compose,
so the previous adding of it is a mistake, now remove it.
also gray out the case for Fedora.

CC: Jiri Zupka <jzupka@redhat.com>
Signed-off-by: Xiaoqing Wei <xwei@redhat.com>
Merge pull request #1032 from xiaoqing-wei/fedora_ks_fix

quick fix to Fedora - remove a no in compose pkg from ks