Don't attempt to dereference "None" datapath
Don't attempt to dereference "None" datapath

Signed-off-by: Joe Stringer <da02367898403910c66f5d62c3a247888772ce8a@gmail.com>

trungdtbk/ryu-rfproxy,joestringer/ryu-rfproxy,KitL/ryu-rfproxy