Previously SignalStrategy::GetLocalJid() was returning non-normalized
JID. The value was passed as is to the authenticator in
JingleSessionManager::OnSignalStrategyIncomingStanza(). Client used
normalized JID value from SignalingAddress for authentication. As
result authentication was failing for hosts that use mixed-case
accounts. With this change GetLocalJid() is replaced with
GetLocalAddress(), which allows to ensure that JID is normalized on
both ends of connection.

BUG=707833

Review-Url: https://codereview.chromium.org/2798393007
Cr-Commit-Position: refs/heads/master@{#463737}