Update submodule ecl to latest Sun May  2 12:39:08 UTC 2021
Update submodule ecl to latest Sun May  2 12:39:08 UTC 2021

    - ecl in PX4/Firmware (cb999f37d4891ebfbbc21b4ce9b3851888b39ad4): https://github.com/PX4/PX4-ECL/commit/5d34d7a24ef72b826c320a3259ee0ec68b1936df
    - ecl current upstream: https://github.com/PX4/PX4-ECL/commit/a7b8afe420f438554ad90bcba0f1f4872325e75b
    - Changes: https://github.com/PX4/PX4-ECL/compare/5d34d7a24ef72b826c320a3259ee0ec68b1936df...a7b8afe420f438554ad90bcba0f1f4872325e75b

    a7b8afe 2021-04-30 Eike - Allow rangefinder fusion in vision height mode (Fix for #994) (#999)
4ac57d3 2021-04-25 Daniel Agar - EKF: increase fault flags value size to fit current flag bits (> 16)

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