Start NEWS entry for 2.9.0 rc2
Start NEWS entry for 2.9.0 rc2

So far, there is one important change since 2.9.0 rc1, the fix
in cfgupgrade.

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

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