Plane: remove unneeded telemetry_delayed parameter

ArduPlane/GCS_Mavlink.cpp

@@ -432,7 +432,7 @@ uint32_t GCS_MAVLINK_Plane::telem_delay() const
 // try to send a message, return false if it won't fit in the serial tx buffer
 bool GCS_MAVLINK_Plane::try_send_message(enum ap_message id)
 {
-    if (telemetry_delayed(chan)) {
+    if (telemetry_delayed()) {
         return false;
     }
 

ArduPlane/Plane.h

@@ -821,7 +821,6 @@ private:
 
     void send_aoa_ssa(mavlink_channel_t chan);
 
-    bool telemetry_delayed(mavlink_channel_t chan);
     void gcs_data_stream_send(void);
     void gcs_update(void);
     void gcs_send_airspeed_calibration(const Vector3f &vg);