MINOR: tcp-rules: Always set from which ruleset a rule comes from

MINOR: tcp-rules: Always set from which ruleset a rule comes from

The ruleset from which a TCP rule comes from (the <from> field in the act_rule
structure) is only set when a rule is created from a registered keyword and not
for all TCP rules. But this information may be useful to check the configuration
validity or during the rule evaluation. So now, we systematically set it.