Pass --disablerepo and --enablerepo to mock
Mockbuild: pass arguments '--disablerepo' and '--enablerepo' to 'mock'
command. Both arguments can be used multiple times.
JIRA: COMPOSE-3367
Fixes: https://pagure.io/fedpkg/issue/313
Signed-off-by: Ondrej Nosek <onosek@redhat.com>