Re: [sr-dev] [kamailio/kamailio] pv: log uninit $var() (PR #3114)

Consider this scenario: 1'st part: ``` if (is_present_hf("SOME_HEADER")) { $var(data) = _get_data_from_some_header_; } ```

2'nd part, later: ``` if ($var(data) != "") { _do_something_with_data_ } ```

2'nd part gets called even for SIP that does not have SOME_HEADER header, with value set in previous SIP that had SOME_HEADER.

I wanted to log a warning for this, so if SIP with no SOME_HEADER header comes in first, in one routing process, I will see the warning log and know to set ```$var(data)="";``` before the 1'st part.

Thank you, Stefan