after-release fixes

[Michal Novotny]

Hello, since the release on Monday, we have implemented and deployed the
following fixes:

- fixed building in epel-7-ppc64le chroot (by temporarily switching of
nosync mock plugin on ppc64le until we have better fix:
https://github.com/kjn/nosync/issues/3#issuecomment-353176672)
- fixed make-srpm build method by providing /etc/mock/default.cfg that is
missing in mock-1.3.4 being currently under use until new mock is released
- deployed backend-1.110 that contains fix for the backend repo
hit-counting script

Thank you if you build in COPR
COPR team