LP#1463459: make SC Status handler recognize logged-in SIP session

LP#1463459: make SC Status handler recognize logged-in SIP session

Due to MsgType not having an account field, handle_sc_status should
be checking $server, not $self, for account information. As a result
of checking the wrong field handle_sc_status always assumes the
session is not logged in and returns status based on the first account.

When this account is not flagged for some capabilities and the client
expects/needs those capabilities the client may determine it can't
function and disconnect, even though the login actually has those
capabilities. This patch fixes that; it also adjusts how
$server->{account} is checked (definedness, not existence).

Signed-off-by: Thomas Berezansky <tsbere@mvlc.org>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>