Remove unused constructor from VCMPacket.

BUG=
R=pbos@webrtc.org, sprang@webrtc.org

Review URL: https://codereview.webrtc.org/2110663004 .

Cr-Original-Commit-Position: refs/heads/master@{#13325}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 37f93af0323fe28688192bc9e3c889903466f37d
3 files changed