commit 294304e4c522d797b7ea8200ab74354843fa68e9 upstream

We have no explicit signal when a UDP stream has terminated, peers just
stop sending.

For suspected stream connections a timeout of two minutes is sane to keep
NAT mapping alive a while longer.

It matches tcp conntracks 'timewait' default timeout value.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NTony Lu <tonylu@linux.alibaba.com>
Acked-by: NDust Li <dust.li@linux.alibaba.com>