net/sngrep: Update to 1.4.8

From ChangeLog: https://github.com/irontec/sngrep/releases/tag/v1.4.8

• capture: add support for IPv6 SDP connection address
• capture: fixed a crash while parsing INVITES without R-URI
• capture: fixed a crash while parsing malformed Req/Resp lines
• call flow: improved IPv6 RTP columns address display
• core: code cleanup removing unused variables
• core: fixed multiple snprintf memory overflows
• core: avoid crash when linking against ncurses without tinfo

PR: 251120
Submitted by: daniel.engberg.lists@pyret.net
Approved by: tad@vif.com (maintainer)