firewalllog.dat: Proper display protocol names.

firewalllog.dat: Proper display protocol names.

In some cases iptables logs the protocol number instead of the name.
When accessing the logs via the WUI, this number has been displayed as used
protocol, which is very hard to read and understand.

This commit adds a new function to the general-functions.pl, which
generates a hash to translate the protocol number into the protocol
name.

Fixes #11282.

Signed-off-by: Stefan Schantl <stefan.schantl@ipfire.org>
Reviewed-by: Michael Tremer <michael.tremer@ipfire.org>
Reviewed-by: Bernhard Bitsch <bbitsch@ipfire.org>
Signed-off-by: Arne Fitzenreiter <arne_f@ipfire.org>