json: Fix tproxy support regarding latest changes

json: Fix tproxy support regarding latest changes

Family may be specified also if no address is given at the same time,
make parser/printer tolerant to that. Also fix for missing/incorrect
JSON equivalents in tests/py.

While being at it, fix two issues in non-JSON tests:

* Ruleset is printed in numeric mode, so use 'l4proto 6' instead of
  'l4proto tcp' in rules to avoid having to specify expected output for
  that unrelated bit.

* In ip and ip6 family tables, family parameter is not deserialized on
  output.

Fixes: 3edb96200690b ("parser_bison: missing tproxy syntax with port only for inet family")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>