expr: nat: Do not print unset values in xml file

It changes the parse functions to omit unset values.

Now, It possible to use a xml file like this:
[...]
<expr type="nat">
        <type>snat</type>
        <family>ip</family>
        <sreg_addr_min>1</sreg_addr_min>
        <sreg_addr_max>1</sreg_addr_max>
</expr></rule>

Signed-off-by: Ana Rey <anarey@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

0 files changed, 0 insertions, 0 deletions