qnd: only perform MySQL operations IF the DB_HOST is us && mysql-server is installed.


git-svn-id: svn+ssh://kelev.kaltura.com/usr/local/kalsource/backend/server/trunk/on-premise/all@96925 6b8eccd3-e8c5-4e7d-8186-e12b5326b719
qnd: adapted to github paths