talk/p2p/base: removed unused variable "port_"
talk/p2p/base: removed unused variable "port_"

BUG=N/A
R=pbos@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/30419004

Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 4a5061fbff6f752c0e25b6f4ffbe025823ca50e9

sippet/talk,sippet/talk,sippet/talk,sippet/talk,sippet/talk