Copter: accept MISSION_START commands when vehicle is disarmed

ArduCopter/GCS_Mavlink.cpp

@@ -796,8 +796,7 @@ MAV_RESULT GCS_MAVLINK_Copter::handle_command_long_packet(const mavlink_command_
 
 #if MODE_AUTO_ENABLED == ENABLED
     case MAV_CMD_MISSION_START:
-        if (copter.motors->armed() &&
-            copter.set_mode(Mode::Number::AUTO, ModeReason::GCS_COMMAND)) {
+        if (copter.set_mode(Mode::Number::AUTO, ModeReason::GCS_COMMAND)) {
             copter.set_auto_armed(true);
             if (copter.mode_auto.mission.state() != AP_Mission::MISSION_RUNNING) {
                 copter.mode_auto.mission.start_or_resume();