updated pjsip stack
There is still a bug on incoming calls when buiding for android
diff --git a/jni/pjproject-android/pjsip/include/pjsip-ua/sip_inv.h b/jni/pjproject-android/pjsip/include/pjsip-ua/sip_inv.h
index 1bb0360..5782cf9 100644
--- a/jni/pjproject-android/pjsip/include/pjsip-ua/sip_inv.h
+++ b/jni/pjproject-android/pjsip/include/pjsip-ua/sip_inv.h
@@ -1,4 +1,4 @@
-/* $Id: sip_inv.h 4562 2013-07-15 04:23:31Z ming $ */
+/* $Id$ */
 /* 
  * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com)
  * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org>
@@ -172,6 +172,10 @@
      * #pjsip_inv_set_sdp_answer() and the re-INVITE will be answered
      * automatically.
      *
+     * Remarks: Application may need to monitor on_tsx_state_changed()
+     * callback to check whether the re-INVITE is already answered
+     * automatically with 487 due to being cancelled.
+     *
      * @param inv	The invite session.
      * @param offer	Remote offer.
      * @param rdata     The received re-INVITE request.