add selective challenge to sofia via reject app

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@5297 d0543943-73ff-0310-b7d9-9358b9ac24b2

src/switch_channel.c

@@ -96,6 +96,7 @@ static struct switch_cause_table CAUSE_CHART[] = {
 	{"BLIND_TRANSFER", SWITCH_CAUSE_BLIND_TRANSFER},
 	{"ATTENDED_TRANSFER", SWITCH_CAUSE_ATTENDED_TRANSFER},
 	{"ALLOTTED_TIMEOUT", SWITCH_CAUSE_ALLOTTED_TIMEOUT},
+	{"USER_CHALLENGE", SWITCH_CAUSE_USER_CHALLENGE},
 	{NULL, 0}
 };