Change design to install to ${PREFIX}/lib/ganeti-${VERSION}
Change design to install to ${PREFIX}/lib/ganeti-${VERSION}

Even though the ${PREFIX}/opt/ only came into the design in the review
process, it is not the best choice, as /opt is reserverd for manually
installed software, but Ganeti intends to be packaged. Use ${libdir}
instead, defaulting to ${PREFIX}/lib.

Signed-off-by: Klaus Aehlig <4ce51de36d9068cd7db2eec1151e0f3f95419008@google.com>
Reviewed-by: Guido Trotter <f62ca4d5358bdaeef0e50e57f9f7e231de63727e@google.com>

leshchevds/ganeti,bitemyapp/ganeti,mbakke/ganeti,yiannist/ganeti,apyrgio/ganeti,onponomarev/ganeti,yiannist/ganeti,ganeti/ganeti,apyrgio/ganeti,mbakke/ganeti,ganeti/ganeti,andir/ganeti,yiannist/ganeti,ganeti-github-testing/ganeti-test-1,grnet/snf-ganeti,ganeti/ganeti,apyrgio/snf-ganeti,bitemyapp/ganeti,andir/ganeti,dimara/ganeti,mbakke/ganeti,dimara/ganeti,leshchevds/ganeti,andir/ganeti,ganeti-github-testing/ganeti-test-1,apyrgio/snf-ganeti,leshchevds/ganeti,grnet/snf-ganeti,onponomarev/ganeti