`$siptrace(src_host)` and `$siptrace(dst_host)` now returns value without brackets.
But that is not coherent with the rest of variables returning host part of various uri or socket values, that's the reason I proposed that `$siptrace(src_host)` and `$siptrace(dst_host)` to return the values as it is and introduce new ones `$siptrace(src_hostip)` and `$siptrace(dst_hostip)` to return the values without brackets.