ekf2: selector handle NAN test ratios as uninitilaized
ekf2: selector handle NAN test ratios as uninitilaized

 - requires https://github.com/PX4/PX4-ECL/pull/1020

acfloria/Firmware,acfloria/Firmware,acfloria/Firmware,acfloria/Firmware,acfloria/Firmware,acfloria/Firmware,acfloria/Firmware