pjproject: fix crash in pj_turn_session_on_rx_pkt2()

Instead of letting the TURN session destroy itself when finished, the current
code is overriding the user_data attached to the session. This is not needed
because the turn session will be stopped when the timer will complete and
this can cause some crashes in pj_turn_session_on_rx_pkt2 because the data
is erased while not protected via turn_sock->grp_lock() (mostly in turn_sock.c,
on_data_read)

Change-Id: Ia4a12917711b5534b372cb3a26e9141e5393c569
Gitlab: #299

contrib/src/pjproject/0012-fix-turn-shutdown-crash.patch

+ pjnath/src/pjnath/turn_sock.c | 3 ---
+ 1 file changed, 3 deletions(-)
+
+diff --git a/pjnath/src/pjnath/turn_sock.c b/pjnath/src/pjnath/turn_sock.c
+index a6e192e9f..3fc65aa75 100644
+--- a/pjnath/src/pjnath/turn_sock.c
++++ b/pjnath/src/pjnath/turn_sock.c
+@@ -1396,9 +1396,6 @@ static void turn_on_state(pj_turn_session *sess,
+     if (new_state >= PJ_TURN_STATE_DESTROYING && turn_sock->sess) {
+ 	pj_time_val delay = {0, 0};
+ 
+-	turn_sock->sess = NULL;
+-	pj_turn_session_set_user_data(sess, NULL);
+-
+ 	pj_timer_heap_cancel_if_active(turn_sock->cfg.timer_heap,
+ 	                               &turn_sock->timer, 0);
+ 	pj_timer_heap_schedule_w_grp_lock(turn_sock->cfg.timer_heap,

contrib/src/pjproject/package.json

@@ -16,7 +16,8 @@
         "0001-win-config.patch",
         "0002-win-vs-gnutls.patch",
         "0003-win-vs2017-props.patch",
-        "0011-fix-tcp-death-detection.patch"
+        "0011-fix-tcp-death-detection.patch",
+        "0012-fix-turn-shutdown-crash.patch"
 ],
     "project_paths": [
         "pjlib-util/build/pjlib_util.vcxproj",

contrib/src/pjproject/rules.mak

@@ -56,6 +56,7 @@ pjproject: pjproject-$(PJPROJECT_VERSION).tar.gz .sum-pjproject
 	$(APPLY) $(SRC)/pjproject/0009-add-config-site.patch
 	$(APPLY) $(SRC)/pjproject/0010-fix-pkgconfig.patch
 	$(APPLY) $(SRC)/pjproject/0011-fix-tcp-death-detection.patch
+	$(APPLY) $(SRC)/pjproject/0012-fix-turn-shutdown-crash.patch
 ifdef HAVE_ANDROID
 	$(APPLY) $(SRC)/pjproject/0001-android.patch
 endif