In both the connection and disconnection sequences, we keep the context in the
private info of the Bearer object, so that we can complete and free it when we
receive %IPDPACT unsolicited messages. Now, the reply of the %IPDPACT itself may
get processed as an unsolicited message, so effectively we're processing and
finishing the connection/disconnection context *before* we process the reply of
the AT command.
This patch ensures that we do not try to re-use the connection/disconnection
context after it has been processed by the unsolicited messages handler.
d065dd572b