Update config version number when downgrading
Update config version number when downgrading

The downgrade option of the cfgupgrade tool was not changing the version
number in the configuration file of the cluster while performing the
downgrade.

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

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