Get engine unit test working without any opensync installation.
Get engine unit test working without any opensync installation.

Missing description directory would let the discover proxies of the
members fail (engine testcase). To avoid this, just ignore if there is
no description directories...


git-svn-id: e31799a7ad59d6ea355ca047c69e0aee8a59fcd3@2949 53f5c7ee-bee3-0310-bbc5-ea0e15fffd5e

ianmartin/opensync,ianmartin/opensync