crypto/tls: fix decoding of certLen in certificateMsg.unmarshal
crypto/tls: fix decoding of certLen in certificateMsg.unmarshal

certLen was decoded incorrectly if length > 2^16-1.

R=golang-dev, agl
CC=golang-dev
http://codereview.appspot.com/6197077

Committer: Adam Langley <db68fba232b2c49ed3e9d3081df349dde7b61dfd@golang.org>

apparentlymart/golang,apparentlymart/golang,dsriram/golang,dsriram/golang,tv42/old-go,pombredanne/go-deleteme,gnanderson/go,apparentlymart/golang,dsriram/golang,dsriram/golang,pombredanne/go-deleteme,dsriram/golang,tv42/old-go,gnanderson/go,dsriram/golang,pombredanne/go-deleteme,pombredanne/go-deleteme,tv42/old-go,gnanderson/go,pombredanne/go-deleteme,gnanderson/go,gnanderson/go,tv42/old-go,pombredanne/go-deleteme,gnanderson/go,pombredanne/go-deleteme,apparentlymart/golang,gnanderson/go,apparentlymart/golang,tv42/old-go,dsriram/golang,apparentlymart/golang,tv42/old-go,apparentlymart/golang,tv42/old-go