[reSIProcate] NULL Pointer crash with resip 1.3.3

[Scott Godin]

> I'll test your patch out and also combine it with my patch for removing the
> use of mRemoteTarget as the new To when onRequestRetry is properly called.

Great - thanks.

> If I understand your changes correctly, onRequestRetry should now only be
> called for timeouts/errors of the initial SUBSCRIBE and any reSUBSCRIBE
> messages.

Yup - that's correct.

Scott