Update NEWS with failover cleanup
Update NEWS with failover cleanup

Describe the new feature in the NEWS file.

Signed-off-by: Michele Tartara <05f7077a2c6cbbdc4af4ba42e3ef89a0df846179@google.com>
Reviewed-by: Guido Trotter <f62ca4d5358bdaeef0e50e57f9f7e231de63727e@google.com>

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