set rtp stack into optimal mode for transferring data during fax situations (that does not mean we support the idea of audio fax over ip......)

src/include/switch_types.h

@@ -872,6 +872,7 @@ typedef enum {
 	SWITCH_MESSAGE_INDICATE_RECOVERY_REFRESH,
 	SWITCH_MESSAGE_INDICATE_SIGNAL_DATA,
 	SWITCH_MESSAGE_INDICATE_INFO,
+	SWITCH_MESSAGE_INDICATE_AUDIO_DATA,
 	SWITCH_MESSAGE_INVALID
 } switch_core_session_message_types_t;