Copter: removed check on target component in arm

Thanks to DonLakeFlyer for finding this, see
https://github.com/diydrones/ardupilot/pull/909

ArduCopter/GCS_Mavlink.pde

@@ -1240,7 +1240,6 @@ void GCS_MAVLINK::handleMessage(mavlink_message_t* msg)
             break;
 
         case MAV_CMD_COMPONENT_ARM_DISARM:
-            if (packet.target_component == MAV_COMP_ID_SYSTEM_CONTROL) {
             if (packet.param1 == 1.0f) {
                 // run pre_arm_checks and arm_checks and display failures
                 pre_arm_checks(true);
@@ -1256,9 +1255,6 @@ void GCS_MAVLINK::handleMessage(mavlink_message_t* msg)
             } else {
                 result = MAV_RESULT_UNSUPPORTED;
             }
-            } else {
-                result = MAV_RESULT_UNSUPPORTED;
-            }
             break;
 
         case MAV_CMD_DO_SET_SERVO: